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
In EPT most efficient site of testing for posterior is: 
Select and explain. 
A. Cusp tip of the mesiobuccal cusp, B. Cusp tip of the mesiolingual cusp., C. Equal over all the cus tips., D. None.
A: Cusp tip of the mesiobuccal cusp
Answer: A: Cusp tip of the mesiobuccal cusp 
Explanation: For incisors- incisal edge is the most efficient site.
For posteriors- mesiobuccal cus tip is the best site.