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
The type of load on teeth that is most destructive to the periodontium is: 
Select and explain. 
A. Vertical, B. Oblique, C. Horizontal, D. Apical
C: Horizontal
Answer: C: Horizontal 
Explanation: None