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': 'A surgical obturator has to be inserted \nSelect and explain. \nA. One day prior to the surgery, B. On the day of the surgery, C. 14 days after the surgery, D. 30 days after the surgery', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]