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 Aoic regurgitation is seen in all 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: Answer is B (Acute myocardial infarction) All options other than acute myocardial infarction are known causes for acute aoic regurgitation. Aoic regurgitation may result from Two Major Mechanisms : allow regurgitation of blood back into LV. I. By causing valvular deformities. This is the most common cause 2. By deforming the aoic root.', 'role': 'assistant'}]