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
Composition of Varnish is: 
Select and explain. 
A. 10% copal resin+90%solvent, B. 90% copal resin+10%solvent, C. 50% copal resin+50% solvent, D. 39% copal resin+70%solvent
A: 10% copal resin+90%solvent
Answer: A: 10% copal resin+90%solvent 
Explanation: None