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
Optimal anti-rotational design in a blade is incorporated by offset not greater than? 
Select and explain. 
A. 2 mm, B. 5 mm, C. 3 mm, D. 6 mm
A: 2 mm
Answer: A: 2 mm 
Explanation: None