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
According to ISO 6876-2001 ADA specifications 57 Endodontics sealer penetration is upto? 
Select and explain. 
A. 150 μm, B. 50 μm, C. 300 μm, D. 100 μm
B: 50 μm
Answer: B: 50 μm 
Explanation: None