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
False about GG drill is 
Select and explain. 
A. NO. 4 is 1.1 mm in size, B. Operated at 750-1500 rpm, C. Used for coronal flaring of root canal, D. Used for preparing post space
D: Used for preparing post space
Answer: D: Used for preparing post space 
Explanation: None