Final answer:
The CR (central ray) should be directed to the center of the part of greatest interest to avoid foreshortening.
Step-by-step explanation:
The CR (central ray) should be directed to the center of the part of greatest interest to avoid foreshortening. Foreshortening is a distortion effect that occurs when an object is photographed or viewed at an angle, causing it to appear shorter or compressed. By directing the CR to the center of the part of greatest interest, you can minimize this distortion and accurately represent the object. This is particularly important in fields like photography, art, and forensics, where accurately portraying objects and details is crucial.