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
[{'content': 'Coefficient of thermal expansion of metal-ceramic alloys is: \nSelect and explain. \nA. Same as porcelain, B. More than porcelain, C. Less than porcelain, D. More than or equal to porcelain but not less', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]