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: Anatomy
[{'content': 'Medial boundary of anatomical snuff box is formed by ? \nSelect and explain. \nA. Extensor pollicis longus, B. Extensor pollicis brevis, C. Abductor pollicis longus, D. Flexor carpi ulnaris', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Extensor pollicis longus", 'role': 'assistant'}]