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: Orthopaedics
[{'content': "Tennis elbow', is characterized by - \nSelect and explain. \nA. Tenderness over the medial epicondyle, B. Tendinits of common extensor origin, C. Tendinitis of common flexor origin, D. Painful flexion and extension", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Tennis elbow is extraarticular affection characterized by pain and acute tenderness at the origin of the extensor muscles of the forearm from the lateral epicondyle.\nIt is believed to be caused by a strain of the forearm extensor muscles, particularly the extensor carpi radialis brevis, at the point of their origin from lateral epicondyle.', 'role': 'assistant'}]