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
A pin retained amalgam: 
Select and explain. 
A. Does not reinforce the tooth, B. Weakens the tooth, C. Reinforces the amalgam structure, D. Improves retention of restoration
D: Improves retention of restoration
Answer: D: Improves retention of restoration 
Explanation: None