Which of the following statements is FALSE?

a. A sterile cotton roll may be placed on the opposite side of the bite block 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 bite block firmly enough to hold the image receptor in place.
d. The bite block back plate must be at a 105-degree angle for use with the paralleling technique

d. To achieve parallelism, the bite block back plate 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 bite block back plate that is at a 105-degree angle for use with the bisecting technique.