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
Which tendon is affected is lateral epicondylitis? 
Select and explain. 
A. Extensor Carpi Radialis Brevis, B. Extensor Carpi Radialis Longus, C. Flexor Pollicis Longus, D. Supinator
A: Extensor Carpi Radialis Brevis
Answer: A: Extensor Carpi Radialis Brevis 
Explanation: 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".