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: Surgery
Mainly elevators in exodontia works on the principle of 
Select and explain. 
A. Lever I., B. Lever I & II., C. Lever III, D. Wedge
A: Lever I.
Answer: A: Lever I. 
Explanation: None