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
Amount of fluoride in amalgam is 
Select and explain. 
A. 8% SnF2, B. 10% SnF2, C. 1% NaF, D. 1% SnF2
D: 1% SnF2
Answer: D: 1% SnF2 
Explanation: None