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
The percentage of unconsumed alloy in low copper amalgams is: 
Select and explain. 
A. 20, B. 9.2, C. 8.8, D. 10
C: 8.8
Answer: C: 8.8 
Explanation: None