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 involvement with no radio graphic evidence is \nSelect and explain. \nA. Grade II, B. Advanced grade II, C. Grade I, D. Early grade III', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]