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
Admixed high copper alloy powder contains 
Select and explain. 
A. 9-20% copper, B. 13-20% copper, C. 9-30% copper, D. 13-30% copper
A: 9-20% copper
Answer: A: 9-20% copper 
Explanation: None