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': 'Conventional glazed dental porcelain is approximately ____times as abrasive as gold to tooth enamel \nSelect and explain. \nA. 10, B. 20, C. 30, D. 40', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Conventional glazed dental porcelain is approximately 40 times as abrasive as gold to tooth enamel', 'role': 'assistant'}]