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
Periodontal ligament is 
Select and explain. 
A. Narrower on mesial surface, B. Wider on mesial surface, C. Equal on both the surfaces, D. Wider in the anterior teeth
A: Narrower on mesial surface
Answer: A: Narrower on mesial surface 
Explanation: None