Which of the following statements is false?

A) A sterile cotton roll may be placed on the opposite side of the biteblock for stabilization of the image receptor holder.
B) The external indicator ring attachment must be as close to the patient's skin as possible without touching.
C) The patient must bite down on the biteblock firmly enough to hold the image receptor in place.
D) The biteblock backplate must be at a 105-degree angle for use with the paralleling technique.

D
Explanation: A) To achieve parallelism, the biteblock backplate must be at a 90-degree angle for use with the parallelling technique. The position of the image receptor close to the teeth requires a biteblock backplate that is at a 105-degree angle for use with the bisecting technique.
B) To achieve parallelism, the biteblock backplate must be at a 90-degree angle for use with the parallelling technique. The position of the image receptor close to the teeth requires a biteblock backplate that is at a 105-degree angle for use with the bisecting technique.
C) To achieve parallelism, the biteblock backplate must be at a 90-degree angle for use with the parallelling technique. The position of the image receptor close to the teeth requires a biteblock backplate that is at a 105-degree angle for use with the bisecting technique.
D) To achieve parallelism, the biteblock backplate must be at a 90-degree angle for use with the parallelling technique. The position of the image receptor close to the teeth requires a biteblock backplate that is at a 105-degree angle for use with the bisecting technique.