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': 'Newly formed PDL fibers are aligned perpendicular to resected root surface after: \nSelect and explain. \nA. 1 week, B. 2 week, C. 4 week, D. 8 week', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]