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: Pathology
[{'content': 'Commonest complication of prosthetic valve is - \nSelect and explain. \nA. Embolism, B. Subacute bacterial endocarditis, C. Rejection, D. Infarction', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]