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
Apex locator reading 00? 
Select and explain. 
A. 0.5-1 mm, B. 0.75-1 mm, C. 0.25-0.mm, D. 0.5-0.75 mm
A: 0.5-1 mm
Answer: A: 0.5-1 mm 
Explanation: None