This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': 'An early systolic murmur may be caused by all of the following except \nSelect and explain. \nA. Small ventricular septal defect, B. Papillary muscle dysfunction, C. Tricuspid regurgitation, D. Aoic stenosis', 'role': 'user'}, {'content': "Answer: D \nExplanation: Aoic stenosis is characteristically associated with a midsystolic murmur and is the most appropriate answer.Ref: Harrison's 18/e p1827-28.", 'role': 'assistant'}]