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
High copper dental amalgams are superior to other amalgams because high copper dental amalgams: 
Select and explain. 
A. Have less marginal breakdown, B. Are workable at lower Hg-alloy ratio, C. Have a higher ratio of tensile to compressive strength, D. Have less resistance to tarnish and corrosion
A: Have less marginal breakdown
Answer: A: Have less marginal breakdown 
Explanation: None