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
Distance of the blade from the shank to have antirotational stability of the instrument? 
Select and explain. 
A. 2 mm, B. 3 mm, C. 4 mm, D. 5 mm
A: 2 mm
Answer: A: 2 mm 
Explanation: None