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
For making an anti-rotational groove, the minimum offset of the edge from the bur axis should not be greater than: 
Select and explain. 
A. 2 mm, B. 4 mm, C. 6 mm, D. 10 mm
A: 2 mm
Answer: A: 2 mm 
Explanation: None