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': 'Most common nerve involvement in fracture surgical neck humerus - \nSelect and explain. \nA. Axillary nerve, B. Radial nerve, C. Ulnar nerve, D. Median nerve', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Axillary nerve is particularly vulnerable, both from the injury and from surgery.', 'role': 'assistant'}]