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': 'At the CEJ cementum overlaps enamel about \nSelect and explain. \nA. 55 to 60%, B. 60 to 65%, C. 65 to 70%, D. 70 to 75%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]