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
Newly formed PDL fibers are aligned perpendicular to resected root surface after: 
Select and explain. 
A. 1 week, B. 2 week, C. 4 week, D. 8 week
D: 8 week
Answer: D: 8 week 
Explanation: None