This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
[{'content': 'Which tendon is affected is lateral epicondylitis? \nSelect and explain. \nA. Extensor Carpi Radialis Brevis, B. Extensor Carpi Radialis Longus, C. Flexor Pollicis Longus, D. Supinator', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., Extensor Carpi Radialis Brevis Tennis elbow* Tennis elbow is a type of repetitive strain injury resulting from tendon overuse and failed healing of the tendon.* The extensor carpi radialis brevis muscle plays a key role.* Histological findings include granulation tissue, microrupture, degenerative changes, and there is no traditional inflammation.As a consequence, "lateral elbow tendinopathy or tendinosis" is used instead of "lateral epicondylitis".', 'role': 'assistant'}]