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: Dental
[{'content': 'The percentage of upper and lower first molars, where furcation entrance diameter is narrower than the width of conventional periodontal curette is \nSelect and explain. \nA. 28%, B. 58%, C. 82%, D. 85%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]