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
Epsilon in high copper amalgam  is? 
Select and explain. 
A. Cu6Sn5, B. Ag3Sn, C. Cu3Sn, D. Ag2Hg3
C: Cu3Sn
Answer: C: Cu3Sn 
Explanation: None