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 number 12 in a 3 unit formula 12-6-8 indicates the blade is 
Select and explain. 
A. 12 mm in length, B. 1.2 mm in length, C. 12 mm in width, D. 1.2 mm in width
D: 1.2 mm in width
Answer: D: 1.2 mm in width 
Explanation: None