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': 'Cementum covers resected root end in: \nSelect and explain. \nA. 12 days, B. 20 days, C. 28 days, D. 8 weeks', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Proliferation of granulation tissue from the severed PDL was observed at 4 days, and the tissue had completely encapsulated the root end\xa0at 8 days. In the experimental groups, cementum deposition was observed at 12 days, and\xa0by 16 days, cementum covered more than 50% of the surface areas of the resected root ends.\xa0\nThe complete healing will take around 4 weeks.', 'role': 'assistant'}]