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': 'All produce continuous murmurs except - \nSelect and explain. \nA. Mitral valve prolapse, B. Arterio venous malfromations, C. Ruptured sinus of valsalva, D. PDA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]