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 optimal orthodontic force per square centimeter of the root surface area is held to be: 
Select and explain. 
A. 18-22 gms, B. 18-26 gms, C. 20-26 gms, D. 26-30 gms
C: 20-26 gms
Answer: C: 20-26 gms 
Explanation: None