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': 'The best age of starting fluoride supplementation \nSelect and explain. \nA. Birth, B. 1 month, C. 2 year, D. 3 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dietary Fluoride Supplementation Schedule', 'role': 'assistant'}]