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': "Deflouridating material is: \nSelect and explain. \nA. Duraphat, B. Fluorprotector, C. Brudevold's solution, D. alumina", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]