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': "Furcation is measured by \nSelect and explain. \nA. Naber's probe, B. Fluoride probe, C. Miller's probe, D. CPITN probe", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]