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': 'The elevator can be used to advantage when: \nSelect and explain. \nA. The tooth to be extracted is isolated, B. The interdental bone is used as a fulcrum, C. The adjacent tooth is not to be extracted, D. Multiple adjacent teeth are to be extracted', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]