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
Size of znpo4 used for luting? 
Select and explain. 
A. 25 Microns, B. 40 Microns, C. 45 microns, D. 15 Microns
A: 25 Microns
Answer: A: 25 Microns 
Explanation: None