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
Best way to prevent caries is: 
Select and explain. 
A. Systematic fluoridation, B. Fluoride mouthwash, C. Fluoride toothpaste, D. Fluoride prophylaxis
A: Systematic fluoridation
Answer: A: Systematic fluoridation 
Explanation: None