1.針對男性腰椎攝影AP axial L5-S1 projection，其中心射束（central ray, CR）之角度對位何者正確？ (A)cephalad 30°、CR to the level of the ASIS（anterior superior iliac spine）at the midline of the body (B)cephalad 15°、CR to the level of the iliac crest at the midline of the body (C)caudad 30°、CR to the level of the ASIS（anterior superior iliac spine） at the midline of the body (D)caudad 15°、CR to the level of the iliac crest at the midline of the body