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
Coefficient of thermal expansion of metal-ceramic alloys is: 
Select and explain. 
A. Same as porcelain, B. More than porcelain, C. Less than porcelain, D. More than or equal to porcelain but not less
D: More than or equal to porcelain but not less
Answer: D: More than or equal to porcelain but not less 
Explanation: None