Explanation:
The correct option is 'd'. A pelvic binder should be centered strictly over the greater trochanters of the femurs. This positioning creates a mechanical vector that effectively reduces the pelvic volume and closes an open-book pelvic injury (symphysis diastasis), providing a tamponade effect on presacral venous bleeding. Placing the binder too high (over the iliac crests or abdomen) is ineffective and can actually worsen the pelvic deformity or compromise respiratory mechanics.

Reference: Routt ML Jr, Falicov A, Woodhouse E, Schildhauer TA. Circumferential pelvic antishock sheeting: a temporary resuscitation aid. J Orthop Trauma. 2002;16(1):45-48.