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
Motion of use for reamers is 
Select and explain. 
A. Pulling or rasping, B. Linear to and fro, C. Penetration retracton and rotation, D. Circumferential
C: Penetration retracton and rotation
Answer: C: Penetration retracton and rotation 
Explanation: None