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
Moisture contamination of amalgam can lead to: 
Select and explain. 
A. Marginal breakdown, B. Shrinkage, C. Delayed expansion, D. Increased stresses
C: Delayed expansion
Answer: C: Delayed expansion 
Explanation: None