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 of amalgam restoration: 
Select and explain. 
A. Can extend upto a depth of 100 - 500 μm, B. Decreases if tin content of alloy increase, C. Is promoted by gama phase of alloy particles, D. Is resisted the most by copper-tin phase in high copper amalgams
A: Can extend upto a depth of 100 - 500 μm
Answer: A: Can extend upto a depth of 100 - 500 μm 
Explanation: None