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': "Anatomic form of roots of teeth is determined by \nSelect and explain. \nA. Dental lamina, B. Neural crest cells, C. Hertwig's root sheath, D. Hammock ligament", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]