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
Corrosion product of high copper amalgam 
Select and explain. 
A. SnO, B. SnHg, C. Sn-O Cl, D. Cu-sn
A: SnO
Answer: A: SnO 
Explanation: None