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
Chlorhexidine used for hand disinfection uses
concentration 
Select and explain. 
A. 1%, B. 0.50%, C. 0.20%, D. 0.12%
A: 1%
Answer: A: 1% 
Explanation: None