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
The first number in the instrument formula indicates 
Select and explain. 
A. Length of the blade in centimeters, B. 1/10th of the width, C. angulation of the blade in degrees, D. primary cutting edge angle
B: 1/10th of the width
Answer: B: 1/10th of the width 
Explanation: None