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: Surgery
[{'content': '. Trendelenburg sign is positive due to the involvement of: March 2009 \nSelect and explain. \nA. Gluteum maximus, B. Gluteus medius, C. Psoas major, D. Adductor magnus', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Gluteus Medius', 'role': 'assistant'}]