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': "Acute Aortic regurgitation is seen in all of the following except - \nSelect and explain. \nA. Marfan's syndrome, B. Acute myocardial infarction, C. Bacterial endocarditis, D. Ankylosing spondylitis", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]