This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
[{'content': 'Commonest complication of prosthetic valve is: \nSelect and explain. \nA. Embolism, B. Sub acute bacterial endocarditis, C. Rejection, D. Infarction', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: b', 'role': 'assistant'}]