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
Gates-Glidden drill is: 
Select and explain. 
A. Flexible and used at low speed, B. Flexible and used at high speed, C. Inflexible and used at low speed, D. Inflexible and used at high speed
C: Inflexible and used at low speed
Answer: C: Inflexible and used at low speed 
Explanation: None