This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pelvis and Hip Injury, Subject name: Orthopaedics
[{'content': 'Radiological factors indicating an unstable pelvis are all except: \nSelect and explain. \nA. Posterior sacroiliac complex displacement by > 1 cm, B. Avulsion fracture of sacral or ischial end of the sacrospinous ligament, C. Avulsion fractures of the L5 transverse process, D. Isolated disruption of pubic symphysis with pubic diastasis of 2 cm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Radiographic factors indicating unstable pelvis are: Posterior sacroiliac complex displacement >1cm Avulsion fracture of sacral or ischial end of the sacrospinous ligament. Avulsion fractures of the L5 transverse process Disruption of pubic symphysis with pubic diastasis of 2 cm with posterior pelvic injury or injury to anterior/ posterior sacroiliac ligament or sacrospinous ligaments. Presence of gap rather than impaction in the posterior pelvic ring.', 'role': 'assistant'}]