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: Surgery
[{'content': 'Which of the following nerve is damaged in the fracture of the shaft of the humerus:March, September 2005 \nSelect and explain. \nA. Musculocutaneous nerve, B. Radial nerve, C. Ulnar nerve, D. Median nerve', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Radial NerveRadial nerve injury occurs in up to 18% of cases of fracture shaft humerus.It is most common with middle third fractures, although best known for its association with Holstein-Lewis type distal third fracture, which may entrap or lacerate the nerve as it passes through the intermuscular septum.Most injuries are neurapraxias or axonotmesis; function will return within 3 to 4 months; laceration is more common in open fractures or gunshot injuries.Delayed surgical exploration should be done after 3 to 4 months if there is no evidence of recovery by electromyography or nerve conduction velocity studies.', 'role': 'assistant'}]