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 finger rest established on tooth surfaces on the opposite side of the same arch is known as: 
Select and explain. 
A. Conventional finger rest, B. Opposite arch finger rest, C. Cross - arch finger rest, D. Finger - on - finger rest
C: Cross - arch finger rest
Answer: C: Cross - arch finger rest 
Explanation: None