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
Marginal leakage due to temperature changes commonly seen in 
Select and explain. 
A. Amalgam alloy, B. Unfilled resin, C. filled resin, D. Gold alloy
B: Unfilled resin
Answer: B: Unfilled resin 
Explanation: None