For an AP axial sacral projection, the

1. patient should empty the bladder and colon before the procedure.
2. central ray is angled 15 degrees cephalically.
3. ASISs are positioned at equal distance to the imaging table.
4. hips and knees are flexed.
a. 1 only
b. 2 and 3 only
c. 1, 2, and 3 only
d. 1, 2, 3, and 4

C