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: Anatomy
[{'content': "Paralysis of which of the following muscle causes froment's sign? \nSelect and explain. \nA. Opponen's pollicis, B. Abductor pollicis, C. Adductor pollicis, D. Adductor hallucis longus", 'role': 'user'}, {'content': "Answer: C \nExplanation: Pen test - Median NerveCard test - Ulnar Nerve Egawas test - Ulnar Nerve Froment's sign - Ulnar N.", 'role': 'assistant'}]