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: Surgery
[{'content': 'IVC filter is used in following except - \nSelect and explain. \nA. Massive emboli, B. Negligible size of emboli, C. Repeated emboli, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]