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
Dietary fluoride supplements should be provided to children if water fluoride ppm is 
Select and explain. 
A. 0.6 ppm or lower, B. 0.7 ppm or lower, C. 0.8 ppm or lower, D. 1.0 ppm or lower
A: 0.6 ppm or lower
Answer: A: 0.6 ppm or lower 
Explanation: The natural fluoride content of the water should first be determined. If the natural fluoride content is 0.6 ppm or higher, supplements should not be administered. If the fluoride content is below 0.6 ppm, the administration of fluoride should be considered.