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
Sharpening of dental instruments is helpful in increasing efficiency because 
Select and explain. 
A. reduce slippage and less tissue damage, B. increase tactile sensation, C. decrease muscle fatigue, D. all the above
D: all the above
Answer: D: all the above 
Explanation: None