Where Does the CR Enter the Patient for the AP $\frac{1}{2}$

Where does the CR enter the patient for the AP projection of the lumbar spine?

A) At the level of the iliac crest, centered to the midsagittal plane
B) At the level of the xiphoid process of the sternum, centered to the midcoronal plane
C) At a level 1 $\frac{1}{2}$ inches above the iliac crest, centered to the midcoronal plane
D) The CR entrance point depends on the size of the IR