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: Medicine
[{'content': 'Which of the following is not a feature of pansystolic murmur? \nSelect and explain. \nA. Atrial septal defect, B. Ventricular septal defect, C. Mitral regurgitation, D. Mitral stenosis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]