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': 'Embolectomy should be done within \nSelect and explain. \nA. 4 hours, B. 6 hours, C. 8 hours, D. 10 hours', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Embolectomy should be done within 6\xa0hours as after 6\xa0hours, irreverside changes occur.', 'role': 'assistant'}]