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
In order to have balance in hand instrument: 
Select and explain. 
A. Blade edge should be within 2 mm of the axis of handle, B. Blade edge should be within 2 mm of the axis of shank, C. Blade edge should be within 2.5 mm of the axis of handle, D. Blade edge should be within 2.5 mm of the axis of shank
A: Blade edge should be within 2 mm of the axis of handle
Answer: A: Blade edge should be within 2 mm of the axis of handle 
Explanation: Balance is accomplished by designing the angles of the shank so that the cutting edge of the blade lies within the projected diameter of the handle and nearly coincides with the projected long axis of the handle. For optimal antirotational design, the blade edge must not be positioned away from the axis by more than 1 to 2 mm.
Sturdevants operative dentistry 7th edition page e1