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': 'Secondary cementum is generally confined to: \nSelect and explain. \nA. Cervical third of the root, B. Middle third of the root, C. Apical third of the root No, D. secondary cementum forms', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]