All of the following are demonstrated on an AP Towne’s view except:
a. occipital bone
b. petrous pyramids
c. zygoma
d. sella turcica
d. sella turcica
The main factor controlling contrast on film is?
a. mAs
b. kVp
c. OID
d. SID
b. kVp
All of the following are associated with DJD except:
a. Heberden’s nodes
b. gullwings
c. nonuniform loss of joint space
d. ulnar deviation
d. ulnar deviation
Which is not a feature of slipped femoral capital epiphysis?
a. Abnormal Klein line
b. Increased tear drop distance
c. Varus deformity
d. Facet tropism
d. Facet tropism
Hydroquinone is a(n) _____, which helps to build up blackness on the radiograph.
a. accelerator
b. hardener
c. developing agent
d. preservative
c. developing agent
Spondylos is defined as _____?
a. vertebra
b. skeleton
c. femoral
d. fracture
a. vertebra
Which is not associated with degenerative spondylolisthesis?
a. Joint arthritis is one factor that contributes to degenerative spondylolisthesis.
b. Predominately affects females over 40
c. This condition is also known as pseudospondylolisthesis.
d. Occurs most commonly at L5
d. Occurs most commonly at L5
Spondyloptosis is not associated with which of the following?
a. Bowline of Brailsford
b. Napoleon’s hat sign
c. Gendarme’s sign
d. Grade 3 spondylolisthesis
d. Grade 3 spondylolisthesis
Which of the following is the most common type of idiopathic scoliosis?
a. juvenile
b. infantile
c. nonstructural
d. adolescent
d. adolescent
The SI unit of measure for rem is best represented as which of the following?
a. MeV (mega volts)
b. Sv (sievert)
c. C/kg (coulomb per kilogram)
d. Gy (gray)
b. Sv (sievert)
The dorsiplantar foot radiographic projection does not demonstrate the?
a. cuneiforms
b. metatarsals
c. phalanges
d. posterior tubercle of the calcaneus
d. posterior tubercle of the calcaneus
Uniform loss of joint space affecting both hands would be most likely seen in which condition?
a. RA
b. DJD
c. AS
d. SLE
a. RA
Which is responsible for the swelling of gelatin upon development of x-rays?
a. phenidone
b. sodium sulfite
c. glutaraldehyde
d. sodium carbonate
d. sodium carbonate
Posterior cervical obliques are taken _____ degrees cephalad.
a. 15
b. 10
c. 60
d. 45
a. 15
Which type of spondylolisthesis has a no defect in the pars involving a spina bifida at L5 and sacrum?
a. pseudospondylolisthesis
b. dysplastic
c. type IV
d. traumatic
b. dysplastic
Which reducing agent produces shades of gray on the developing film?
a. glutaraldehyde
b. sodium sulfite
c. potassium bromide
d. phenidone
d. phenidone
Fracture of the _____ is associated with Monteggia fracture.
a. radius
b. ulna
c. tibia
d. femur
b. ulna
Filtration in the x-ray tube is composed of _____?
a. copper
b. lead
c. aluminum
d. tungsten
c. aluminum
Which is not involved with RA?
a. Swan neck deformity
b. Juxta-articular periostitis
c. Ulnar deviation
d. Herberden’s nodes
d. Herberden’s nodes
The AP sacrum projection has a tube tilt of?
a. 45 degrees cephalad
b. 15 degrees cephalad
c. always perpendicular to the cassette
d. 45 degrees caudad
b. 15 degrees cephalad
Which of the following is not associated with multiple pseudo fractures (Looser’s lines)?
a. Rickets
b. Paget’s disease
c. Osteomalacia
d. Psoriatic arthritis
a. Rickets
All of the following are true pertaining to an anterior posterior Towne’s view except:
a. 10x12 film size
b. tube tilt is 35 degrees caudal
c. central ray passes through the external auditory meatus
d. FFD is 72 inches
d. FFD is 72 inches
- Towne’s view = Foramen magnum
All of the following has to do with a fractured radius except:
a. Galeazzi’s fracture
b. Monteggia’s fracture
c. Colles’ fracture
d. Smith’s fracture
b. Monteggia’s fracture
Thurston-Holland sign is associated with Salter-Harris type _____?
a. 1
b. 2
c. 3
d. 4
b. 2
Which type of fracture is most common in childhood?
a. pathologic
b. comminuted
c. greenstick
d. bowing
c. Greenstick
Colles’ fracture occurs at the _____; Smith’s fracture takes place at the _____?
a. radius, radius
b. ulna, ulna
c. radius, ulna
d. ulna, radius
a. radius, radius
Increasing all of the following will increase density on a radiographic image except:
a. mAs
b. OID
c. kVp
d. film-screen speed
b. OID
The body of the “Scotty dog” in a lumbar oblique projection is best represented as the _____?
a. lamina
b. transverse process
c. superior articular process
d. vertebral body
a. lamina
Which type of beam restrictor sometimes comes in a flare type having a distal diameter larger than the proximal diameter?
a. collimator
b. aperture diaphragm
c. cone
d. ionization chamber
c. cone
Dislocation of the lunate is suspected in your patient. Which view is best for this observation?
a. PA finger
b. AP elbow
c. lateral wrist
d. lateral elbow
c. lateral wrist
Which is not a type of phosphor used in modern intensifying screens?
a. lanthanum
b. gadolinium
c. calcium tungstate
d. yttrium
c. calcium tungstate
Which is used to neutralize the developmental residue that is still on the film from processing?
a. water
b. cycon
c. potassium sulfate
d. acetic acid
d. acetic acid
Which type of Salter-Harris classification will have fracture of the growth plate, epiphysis and metaphysis?
a. type I
b. type II
c. type III
d. type IV
d. type IV
All of the following are clearly demonstrated on cervical oblique projections except:
a. pedicles
b. von Luschka joints
c. IVF’s
d. external occipital protuberance
d. external occipital protuberance
Compression of the growth plate is seen in Salter-Harris type _____?
a. 2
b. 3
c. 4
d. 5
d. 5
The central ray is directed at the thyroid cartilage (C4) for which view?
a. AP open mouth
b. AP lower cervical
c. Water’s
d. Caldwell’s
b. AP lower cervical
Xeroradiography is used most commonly for exam of the _____?
a. stomach
b. breast
c. pancreas
d. liver
b. breast
The patient will be exposed with the most radiation when the bucky factor is?
a. 1
b. 4
c. 6
d. 7
d. 7
The anterior cervical oblique has the central ray directed at _____?
a. 15 degrees caudal
b. 90 degrees
c. 45 degrees caudal
d. 25 degrees caudal
a. 15 degrees caudal
Spondylolisthesis occurs most commonly at _____?
a. L4
b. L5
c. L3
d. C4
b. L5
Seat belt fractures are most common at _____?
a. T3-T6
b. L1-L3
c. T5-T8
d. C5-C7
b. L1-L3
Which of the following is at the level of the iliac crest?
a. L1
b. L4
c. S1
d. S2
b. L4
Which of the following patients is most likely to have degenerative spondylolisthesis?
a. female over 40 years of age
b. male over 40 years of age
c. female 20-40 years of age
d. male 20-40 years of age
a. female over 40 years of age
Which of the following helps to get ride of unexposed silver bromide crystals?
a. fixer
b. developer
c. activator
d. reducing agent
a. fixer
Which of the following is not a significant factor in controlling recorded detail on a radiographic image?
a. source-to-image distance (SID)
b. focal spot size
c. grid ratio
d. object-to-image distance (OID)
c. grid ratio
Which would contribute to the lack of fog on film?
a. hardener
b. water
c. restrainer
d. acetic acid
c. restrainer
Which of the following is a component of the fixer that stops the action of the developer in an automatic film processor?
a. acetic acid
b. phenidone
c. hydroquinone
d. potassium bromide
a. acetic acid
All of the following are typical signs observed in generalized osteoporosis except:
a. biconcave vertebra
b. wedged vertebra
c. splenomegaly
d. Schmorl’s nodes
c. splenomegaly
All of the following radiographic projections have a central ray positioned at C4 except:
a. lateral cervical
b. cervical oblique
c. lower cervical
d. swimmer’s
d. swimmer’s
Intensifying screens contain?
a. silver bromide
b. silver halide
c. gelatin
d. phosphors
d. phosphors
The most common type of spondylolytic spondylolisthesis occurs at?
a. L4
b. L5
c. C7
d. T6
b. L5
Which of the following has the greatest effect on the contrast of a radiographic image?
a. kVp
b. mAs
c. central ray angle
d. focal spot size
a. kVp
Fractures of the distal radius with distal fragments going towards the anterior describes?
a. Colles’ fracture
b. Smith’s fracture
c. Monteggia’s fracture
d. Galeazzi’s fracture
b. Smith’s fracture
The SI unit of measure for rad is which of the following?
a. Gy (gray)
b. Sv (sievert)
c. C/kg (coulomb per kilogram)
d. MeV (mega volts)
a. Gy (gray)
A transverse fracture of the fourth metacarpal is which type of fracture?
a. Rolando’s
b. Bennett’s
c. Boxer’s
d. Bar room
d. Bar room
Which is not a radiologic or clinical finding in RA?
a. ADI space is increased
b. Ulnar deviation deformity
c. Increased ESR
d. Romanus lesion
d. Romanus lesion
The David series without the oblique projections consist of how many views?
a. 4
b. 3
c. 5
d. 7
c. 5
Which is not a radiographic sign of neurotrophic arthropathy?
a. jigsaw vertebra
b. Charcot’s joint
c. increased bone density
d. swan neck deformity
d. swan neck deformity
Neurotrophic arthropathy is most likely to occur at which spinal area?
a. cervical
b. lumbar
c. sacrum
d. thoracic
b. lumbar
The maximum permissible dose is _____ mrem.
a. 5000
b. 500
c. 5
d. 100
a. 5000
Which is not a sign of DJD?
a. osteophytes
b. sclerosis
c. reduction of joint space uniformly
d. Waldenstrom’s sign
c. reduction of joint space uniformly
The knee is flexed fully in which projection?
a. AP ankle
b. Tangential projection
c. Lateral knee
d. Tunnel projection
b. Tangential projection
Which of the following occurs most frequently with Down’s syndrome?
a. Schmorl’s nodes
b. posterior ponticle
c. butterfly vertebrae
d. agenesis of the transverse ligament of atlas
d. agenesis of the transverse ligament of atlas
Which type of spondylolisthesis most frequently occurs at L4 and is due to an increase in the pedicle-facet angle?
a. Type I
b. Type II
c. Type III
d. Type IV
c. Type III
A patient presents with a low hairline and a short webbed neck. Which condition is this associated with?
a. brevicollis
b. cervical rib
c. AS
d. RA
a. brevicollis
Which of the following is a radiologic sign of diffuse idiopathic skeletal hyperostosis?
a. star sign
b. dagger spine
c. gull wings
d. ossification of the anterior longitudinal ligament
d. ossification of the anterior longitudinal ligament
The odontoid fuses to the C2 body around age _____.
a. 6
b. 12
c. 18
d. 21
a. 6
Which of the following will have the most significant effect on recorded detail on a radiographic image?
a. kVp
b. mAs
c. OID
d. grid ratio
c. OID
Which is the reducing agent in the automatic film processing that creates gray tones?
a. potassium bromide
b. phenidone
c. hydroquinone
d. glutaraldehyde
b. phenidone
Which would be consider a rheumatoid variant?
a. D.I.S.H
b. AS
c. DJD
d. Fibrous dysplasia
b. AS
All of the following will increase contrast on radiographic film except:
a. decrease kVp
b. increase grid ratio
c. increase collimation
d. increase kVp
d. increase kVp
The standard developing temperature of film processing is _____ degrees Fahrenheit.
a. 60
b. 64
c. 68
d. 72
c. 68
Which grid ratio will require the greatest amount of mAs utilized?
a. 3:1
b. 5:1
c. 8:1
d. 16:1
d. 16:1
All of the following are associated with SLE except:
a. ulnar deviation
b. atlantoaxial instability
c. cardiomegaly
d. gull wings
d. gull wings
The second most common type of spondylolytic spondylolisthesis occurs at?
a. L4
b. L5
c. C7
d. T6
a. L4
The anti-fog agent in film processing is?
a. hydroquinone
b. potassium bromide
c. water
d. acetic acid
b. potassium bromide
The most common causes of neutrophic arthropathy is?
a. AS
b. Diabetes mellitus
c. SLE
d. Metastasis
b. Diabetes mellitus
Which of the following will not cause an increase in ADI space?
a. RA of the cervical spine
b. D.I.S.H. of the cervical spine
c. DJD of the cervical spine
d. Sprengle’s deformity
d. Sprengle’s deformity
The unit of exposure is measured in?
a. rads
b. millirem
c. roentgens
d. millirads
c. roentgens
Which grid ratio will require the most amount of mAs?
a. 5:1
b. 8:1
c. 3:1
d. 16:1
d. 16:1
All of the following will decrease sharpness on x-ray except:
a. small focal spot
b. increase object-to-image distance (OID)
c. smaller source-to-image distance (SID)
d. large focal spot
a. small focal spot
Fracture of the radius distally with radioulnar joint dislocation is called a _____ fracture. Fracture of the growth plate only is a _____.
a. Monteggia’s, type I Salter-Harris
b. Galeazzi’s, type I Salter-Harris
c. Colles’, type III Salter-Harris
d. Smith’s, type III Salter-Harris
b. Galeazzi’s, type I Salter-Harris
Which of the following will reduce density of film?
a. use of a grid
b. increase film screen speed
c. increase mAs
d. increase kVp
a. use of a grid
Posterior ponticus is associated or linked with all of the following except:
a. Barre-Lieou syndrome
b. vertebrobasilar insufficiency
c. calcification of the atlantooccipital ligament
d. varicose veins
d. varicose veins
Which of the following is the most common site of involvement in rheumatoid arthritis?
a. feet and hands
b. shoulder and hip
c. knee and lumbar spine
d. elbow and wrist
a. feet and hands
Distal radius has a fracture with posterior displacement of the hand?
a. Colles’ fracture
b. Monteggia’s fracture
c. Galeazzi’s fracture
d. Smith’s fracture
a. Colles’ fracture
The least common type of spondylolytic spondylolisthesis occurs in?
a. lower lumbar area
b. lower cervical area
c. upper cervical area
d. lower sacrum
b. lower cervical area
Gas on x-ray will appear _____?
a. white
b. closest to the color of gray
c. closest to the color of black
d. bright gray
c. closest to the color of black
Grid frequency can be most accurately defined as:
a. height of the lead strips multiple by the distance separating the lead strips
b. increased quantity of mAs utilized
c. quantity of lead strips per centimeter or inch
d. the number of times a grid must be used to achieve proper exposure
c. quantity of lead strips per centimeter or inch
All of the following are characteristics of DJD except:
a. osteophytes
b. eburnation
c. geodes
d. uniform loss of joint space
d. uniform loss of joint space
Type III spondylolisthesis most commonly occurs at _____?
a. L4
b. L5
c. L3
d. C5
a. L4
Which grid ratio will produce the most contrast?
a. 16:1
b. 10:1
c. 12:1
d. 5:1
a. 16:1
Which is not true of the lateral ankle view?
a. demonstrates ankle joint, fibula, tibia and talus
b. central ray is through medial malleolus
c. taken on a 11x14 film
d. there is no tube tilt
c. taken on a 11x14 film
Which is not a type of finding typically observed in osteoporosis?
a. Wedged vertebra
b. Schmorl’s node
c. Increase in bone density
d. Vertebra plana
c. Increase in bone density
All of the following are incomplete fractures except:
a. comminuted
b. torus
c. greenstick
d. bowing
a. comminuted
Which is the most common element in x-ray beam restriction?
a. Low kVp
b. Film speed
c. Collimator
d. High mAs
c. Collimator
Which of the following is not a type of idiopathic scoliosis?
a. juvenile
b. adolescent
c. infantile
d. nonstructural
d. nonstructural
Cervical ribs are most common at _____?
a. C4
b. C5
c. C3
d. C7
d. C7
What is used to check for platybasia?
a. Martin’s basilar angle
b. ADI space
c. Chamberlain’s line
d. Shenton’s line
a. Martin’s basilar angle
Which is not demonstrated in an AP lower cervical view?
a. Von Luschka Joints
b. Lung apices
c. Trachea
d. Styloid process
d. Styloid process
Which is used as the washing agent in film processing?
a. glutaraldehyde
b. water
c. reducing agent
d. activator
b. water
All of the following are usual causes of neurotrophic arthropathy except:
a. Multiple sclerosis
b. Diabetes mellitus
c. Steroid use
d. Psoriatic arthritis
d. Psoriatic arthritis
The anti-fog agent or restrainer is identified as:
a. glutaraldehyde
b. phenidone
c. potassium bromide
d. sodium carbonate
c. potassium bromide
Which of the following gets ride of the unexposed silver bromide in an automatic film processor?
a. hardener
b. restrainer
c. fixer
d. developer
c. fixer
Which is not demonstrated on a Water’s projection?
a. maxillary sinus
b. zygomatic arch
c. petrous pyramids
d. ethmoid sinus
c. petrous pyramids
- Water’s projection = Maxillary sinus
To double the radiographic density, the 15% rule is applied to which of the following?
a. central ray angle
b. anode heel effect
c. focal spot size
d. kVp
d. kVp
What view should be taken if there is a suspected scaphoid fracture?
a. tangential elbow
b. lateral thumb
c. PA ulnar flexion
d. AP elbow
c. PA ulnar flexion
Facet tropism means the joint between the articular processes are _____?
a. lowering
b. curved
c. plantar
d. straight
b. curved
Which is not demonstrated on a Water’s projection?
a. ethmoid sinus
b. frontal sinus
c. maxillary sinus
d. C3
d. C3
Lumbar obliques are primarily taken to view which of the following?
a. IVF
b. pars
c. spinous processes
d. von Luschka joints
b. pars
Which of the following properties are significantly affected by a change in mAs?
a. density
b. contrast
c. distortion
d. recorded detail
a. density
Blocked vertebrae are most commonly found at _____?
a. C5-C6
b. T12-L1
c. T5-T6
d. L4-L5
a. C5-C6
All of the following will increase contrast on a film except:
a. beam restriction
b. chemical fog
c. fast film screen
d. grids
b. chemical fog
Which is not an appropriate condition for film storage?
a. 45% humidity
b. 68 degrees F
c. 77 degrees F
d. 55% humidity
c. 77 degrees F
Osteonecrosis of the lunate is referred to as _____?
a. Fat pad sign
b. Terry Thomas sign
c. Kienbock’s sign
d. Ring sign
c. Kienbock’s sign
If film is not washed enough during the film processing, what color will the film finally turn?
a. purple
b. red
c. brown
d. blue
c. brown
Which is the best vis to assess anterolisthesis of lumbar vertebra?
a. oblique
b. lateral
c. AP
d. PA
b. lateral
Umbra can be described as _____?
a. blurred object observed on film
b. blurred area around the object on film
c. the true object observed on film
d. the false object observed on film
c. the true object observed on film
Dislocation of the radioulnar joint with fracture of the distal part of the radius describes?
a. Colles’ fracture
b. Smith’s fracture
c. Monteggia’s fracture
d. Galeazzi’s fracture
d. Galeazzi’s fracture
Bouchard’s nodes are observed in the _____ joints and occur in _____?
a. PIP, osteoarthritis
b. DIP, rheumatoid arthritis
c. PIP, rheumatoid arthritis
d. DIP, osteoarthritis
a. PIP, osteoarthritis
Contrast needs to be increased on a radiographic image. Which is the best solution to accomplish this?
a. Decrease kVp by 15%
b. Decrease OID
c. Decrease collimation
d. Decrease grid ratio
a. Decrease kVp by 15%
Which is used as a film preservative in the development process of film?
a. sodium sulfite
b. water
c. sodium carbonate
d. hydroquinone
a. sodium sulfite
The body of the “Scotty dog” is referred to as the _____?
a. lamina
b. transverse process
c. superior articular process
d. pars interarticularis
a. lamina
Which of the following is not an inflammatory disorder?
a. AS
b. Scleroderma
c. SLE
d. DJD
d. DJD
The right IVF is demonstrated when the patient’s back is towards the bucky in a cervical _____.
a. LPO
b. RPO
c. RAO
d. LAO
a. LPO
The Tube tilt in a P to A Caldwell view is _____ degrees caudal.
a. 10
b. 90
c. 15
d. 20
c. 15
- Caldwell view = Frontal sinus
The umbilicus is at the level of which following?
a. T10
b. L1
c. L3
d. T7
c. L3
Which type of spondylolisthesis is due to a fracture of the neural arch without damage to the pars interarticularis?
a. Type I
b. Type II
c. Type III
d. Type IV
d. Type IV
Which is not a radiographic feature of rheumatoid arthritis?
a. Heberden’s nodes
b. Boutonniere deformity
c. Haygarth’s nodes
d. Swan-neck deformity
a. Heberden’s nodes
Total forward displacement of L5 vertebral body beyond sacral promontory is called _____?
a. spondyloptosis
b. grade 4 spondylolisthesis
c. grade 3 spondylolisthesis
d. grade 1 spondylolisthesis
a. spondyloptosis
Butterfly vertebrae are observed most often in the _____?
a. cervical spine
b. lumbar spine and thoracic spine
c. sacrum
d. cervical spine and sacrum
b. lumbar spine and thoracic spine
Which of the following is not true regarding Sprengle’s deformity?
a. Associated with Klippel-Feil syndrome
b. Failure of scapula to descend
c. Many cases also involve an omovertebral bone
d. This occurs mostly in males
d. This occurs mostly in males
Which view has a central ray of the 3rd metatarsal?
a. medial oblique foot
b. lateral foot
c. lateral ankle
d. skyline projection
a. medial oblique foot
Dislocation of the radioulnar joint with fracture of the distal radius is called which type of fracture?
a. Greenstick
b. Galeazzi’s
c. Smith’s
d. Monteggia’s
b. Galeazzi’s
Which does not cause an atlantodental interspace that is too wide?
a. RA
b. Down’s syndrome
c. Reiter’s syndrome
d. Barton’s fracture
d. Barton’s fracture
All of the following increase density of film except:
a. increase kVp
b. increase developing time
c. increase grid ratio
d. increase mAs
c. increase grid ratio
Agenesis of the dens is termed?
a. os odontoideum
b. ossiculum terminale
c. odontoid aplasia
d. spondyloschisis
c. odontoid aplasia
The tube tilt is _____ degrees in the AP ankle film.
a. 15
b. 0
c. 20
d. 45
b. 0
Which of the following is true regarding the Ten-Day Rule?
a. X-rays should be taken 10 days before menstrual period
b. X-rays should be given not more than 10 days after start of menstrual period
c. X-rays should be given 10 days after menstrual period
d. X-rays should never be given during menstrual period
b. X-rays should be given not more than 10 days after start of menstrual period
All of the following are true pertaining to adolescent idiopathic scoliosis except:
a. Hueter-Volkmann principle may be present.
b. This occurs most commonly in females 12-16 years of age.
c. A right convex thoracic type of scoliosis is most common.
d. This is the least common type of idiopathic scoliosis.
d. This is the least common type of idiopathic scoliosis.
Which is demonstrated in a swimmer’s view?
a. thoracics only
b. cervicals only
c. lower cervicals only
d. lower cervicals and upper thoracics
d. lower cervicals and upper thoracics
Type II spondylolisthesis most commonly occurs at _____?
a. L4
b. L5
c. L3
d. C5
b. L5
Which would be found in an intensifying screen?
a. phosphor layer
b. silver bromide
c. silver halide
d. copper
a. phosphor layer
Which condition will have the HLA-B27 antigen, radiographically have mouse ears, pencil in cup deformity, sea gull deformity, and cocktail sausage digits?
a. AS
b. OA
c. RA
d. Psoriatic arthritis
d. Psoriatic arthritis
Focal film distance is changed from 40 inches to 72 inches. Which of the following will occur?
a. object magnification will be decreased
b. object magnification will be increased
c. sharpness of image will be decreased
d. increase in penumbra
a. object magnification will be decreased
Past repeated stress fractures of the pars with elongation would most likely describe which type of spondylolisthesis?
a. dysplastic
b. (traumatic) type IV
c. isthmic subtype b
d. isthmic subtype c
c. isthmic subtype b
A 45-year old female has soft tissue fibromas, polyps in the colon and many osteomas. Which is the most probable condition?
a. Supperative osteomyelitis
b. Fibrous dysplasia
c. Gardeners syndrome
d. Multiple myeloma
c. Gardeners syndrome
What minimum percent change in mAs must there be to see an observable change in radiographic density?
a. 30%
b. 20%
c. 10%
d. 5%
a. 30%
DJD is associated with all of the following except:
a. geodes
b. subchondral sclerosis
c. non-uniform loss of joint space
d. flowing hyperostosis
d. flowing hyperostosis
The left IVF is demonstrated when the patient’s back is towards the bucky in a cervical _____.
a. RPO
b. LPO
c. RAO
d. LAO
a. RPO
