What is the ideal design of a paralleling image receptor holder?

B
Explanation: A) Image receptor holders designed for use with the paralleling technique usually have a long bite block area for the purpose of achieving a parallel relationship between the recording plane of the image receptor and the long axes of the teeth and an L-shaped backing to help support the image receptor and keep it in position.
B) Image receptor holders designed for use with the paralleling technique usually have a long bite block area for the purpose of achieving a parallel relationship between the recording plane of the image receptor and the long axes of the teeth and an L-shaped backing to help support the image receptor and keep it in position.
C) Image receptor holders designed for use with the paralleling technique usually have a long bite block area for the purpose of achieving a parallel relationship between the recording plane of the image receptor and the long axes of the teeth and an L-shaped backing to help support the image receptor and keep it in position.
D) Image receptor holders designed for use with the paralleling technique usually have a long bite block area for the purpose of achieving a parallel relationship between the recording plane of the image receptor and the long axes of the teeth and an L-shaped backing to help support the image receptor and keep it in position.