This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
[{'content': 'Muscle that does not constitute the pelvic diaphragm is: \nSelect and explain. \nA. Puborectalis, B. Iliococcygeus, C. Pubococcygeus, D. Ischiococcygeus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. PuborectalisCoccygeus and ischio coccygeus are one and the same.pelvic diaphragm is composed of pubococcygeus, iliococcygeus and ischio coccygeus.', 'role': 'assistant'}]