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. Aoic stenosis, B. Mitral regurgitation, C. Aoic regurgitation, D. Septal defect', 'role': 'user'}, {'content': "Answer: B \nExplanation: In patients with myocardial infarction, on examination a transient midsystolic or late systolic apical systolic murmur due to dysfunction of the mitral valve apparatus may be present. Other examination findings includes: Usually quiet precordium with difficulty to palpate apical impulse. In anterior wall infarction: an abnormal systolic pulsation caused by dyskinetic bulging of infarcted myocardium may develop in the periapical area Decreased intensity of S1, presence of S3, S4 Paradoxical splitting of S2 A pericardial friction rub is heard in many patients with transmural STEMI at some time in the course of the disease Ref: Harrison's Principles of Internal Medicine, 18e chapter 245.", 'role': 'assistant'}]