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
Increase in the residual mercury in silver amalgam filling can: 
Select and explain. 
A. Cause fracture of the filling, B. Tarnish and corrosion, C. Increase the strength, D. Decrease condensation pressure
A: Cause fracture of the filling
Answer: A: Cause fracture of the filling 
Explanation: None