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
High speed includes the R.P.M between 
Select and explain. 
A. 20000-50000, B. 50000-100000, C. 100000-200000, D. above 200000
B: 50000-100000
Answer: B: 50000-100000 
Explanation: None