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
First flouride varnish discovered in Europe has what percentage of NaF 
Select and explain. 
A. 2.26%, B. 5%, C. 8%, D. 10%
B: 5%
Answer: B: 5% 
Explanation: None