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': 'In a patient with myocardial infarction the valvular lesion commonly seen is \nSelect and explain. \nA. Aortic stenosis, B. Mitral regurgitation, C. Aortic regurgitation, D. Septal defect', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]