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': 'Mitral valve vegetations do not usually embolise to: \nSelect and explain. \nA. Lung, B. Liver, C. Spleen, D. Brain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mitral valve vegetation would obviously not go to the lung, as that would involve a backward flow.', 'role': 'assistant'}]