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
Which of the following fibers restrict extrusion of tooth in orthodontics: 
Select and explain. 
A. Alveolar crest, B. Oblique, C. Apical, D. Horizontal
A: Alveolar crest
Answer: A: Alveolar crest 
Explanation: None