This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Orthopaedics
[{'content': "A physician notes weakness of a patient's thumb in extension, although rotation, flexion, abduction, adduction, and opposition are normal. Which of the following nerves is most likely involved? \nSelect and explain. \nA. Median and radial, B. Median and ulnar, C. Median only, D. Radial only", 'role': 'user'}, {'content': 'Answer: D \nExplanation: All three of the nerves listed innervate muscles that supply the thumb. Extension is provided by the extensors pollicis longus and brevis, which are innervated by the radial nerve. Ref: Maheshwari 6e pg 63,65.', 'role': 'assistant'}]