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
Diameter at D16 of file 35 
Select and explain. 
A. 0.67mm, B. 0.35mm, C. 0.067mm, D. 0.035mm
A: 0.67mm
Answer: A: 0.67mm 
Explanation: None