In Order to Preserve the True Shape of the Part

In order to preserve the true shape of the part in the image,what three factors should be properly aligned? 1.X-ray tube.
2) Image receptor.
3) Object-to-image distance.
4) Anatomic part.

A) 1,2,and 3.
B) 1,3,and 4.
C) 2,3,and 4.
D) 1,2,and 4.