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
Amalgam restorations give the best clinical service when the residual mercury content is: 
Select and explain. 
A. 38-42%, B. 48-52%, C. 58-62%, D. 68-72%
B: 48-52%
Answer: B: 48-52% 
Explanation: None