Which of the following is a basic principle of the paralleling technique?

A) The image receptor is placed perpendicular to the long axes of the teeth.
B) The central ray of the x-ray beam is directed parallel to both the teeth and the recording plane of the image receptor.
C) The image receptor is placed parallel to the long axes of the teeth.
D) The central ray of the x-ray beam is directed perpendicular to an imaginary bisector.

C
Explanation: A) The basic principles of the paralleling technique are that the image receptor (film packet, phosphor plate, or digital sensor) must be placed parallel to the long axis of the object (tooth) being radiographed and that the central ray of the x-ray beam is directed to intersect both the image receptor and the object (tooth) perpendicularly.
B) The basic principles of the paralleling technique are that the image receptor (film packet, phosphor plate, or digital sensor) must be placed parallel to the long axis of the object (tooth) being radiographed and that the central ray of the x-ray beam is directed to intersect both the image receptor and the object (tooth) perpendicularly.
C) The basic principles of the paralleling technique are that the image receptor (film packet, phosphor plate, or digital sensor) must be placed parallel to the long axis of the object (tooth) being radiographed and that the central ray of the x-ray beam is directed to intersect both the image receptor and the object (tooth) perpendicularly.
D) The basic principles of the paralleling technique are that the image receptor (film packet, phosphor plate, or digital sensor) must be placed parallel to the long axis of the object (tooth) being radiographed and that the central ray of the x-ray beam is directed to intersect both the image receptor and the object (tooth) perpendicularly.