This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nerve supply, Nerve Lesions, Subject name: Anatomy
[{'content': 'Median nerve injury at wrist, is commonly tested by:- \nSelect and explain. \nA. Contraction of abductor pollicis brevis, B. Contraction flexor pollicis brevis, C. Contraction opponens pollicis, D. Loss of sensation on palm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Median nerve injury at wrist is commonly subjected to pen test. This test is for the function of abductor pollicis brevis (Draw thumb forwards at right angle to palm) supplied by median nerve. Pen test A pen is kept at a level higher than the thumb and the pt is asked to touch the tip of the pen', 'role': 'assistant'}]