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': 'Treatment time for topical fluoride application on deciduous teeth is \nSelect and explain. \nA. 1 minute, B. 2 minute, C. 3 minute, D. 4 minute', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 4-minute treatment time has been typically recommended for professionally applied topical\xa0fluoride solutions, gels, or foams.', 'role': 'assistant'}]