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': 'Width of the periodontal ligament is least at \nSelect and explain. \nA. Cervical third, B. Apical third, C. Fulcrum of rotation, D. It has uniform width', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]