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
Mechanically, the strongest phase in amalgam restoration is 
Select and explain. 
A. The original gamma phase (Ag3Sn), B. The gamma I phase, C. The gamma II phase, D. The copper — Tin phase
A: The original gamma phase (Ag3Sn)
Answer: A: The original gamma phase (Ag3Sn) 
Explanation: None