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': 'Man comes with head injury investigation of choice \nSelect and explain. \nA. CECT, B. X - ray, C. MRI, D. Plain CT', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer- D. Plain CTInvestigation of choice for head trauma patient is CT scan.', 'role': 'assistant'}]