This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
[{'content': 'The following are radiological features of sigmoid volvulus except – \nSelect and explain. \nA. Inverted U shaped bowel loop, B. Liver overlap sign, C. Bird of prey, D. Cupola sign', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Radiological signs of sigmoid volvulus Liver overlap sign, Flank overlap sign, D10\xa0overlap sign, Coffee bean sign, Bird - of - prey sign, Inverted U/V sign, Omega sign, Bent inner tube / Bent tyre tube.', 'role': 'assistant'}]