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': 'Least common site for vegetation is? \nSelect and explain. \nA. Aoic Stenosis (AS), B. Mitral Stenosis (MS), C. Mitral Regurgitation (MR), D. Atrial Septal Defect (ASD)', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer is D (ASD) Repeat Vegetations of infective endocarditis are least common with ASD amongst the options provided', 'role': 'assistant'}]