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': 'A patient is brought to the emergency with history of trauma to his right upper limb. Extension of metacarpophalangeal is lost. There is no wrist drop and extension of IP joint is normal. The most likely nerve involved is : \nSelect and explain. \nA. Ulnar nerve, B. Median nerve, C. Radial nerve, D. Posterior - interosseous nerve', 'role': 'user'}, {'content': 'Answer: D \nExplanation: When\xa0posterior interosseous nerve is injured, there is thumb and finger drop. Extension of wrist is spared.', 'role': 'assistant'}]