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: Social & Preventive Medicine
Which of the following is the accepted safe level of flouride in drinking water ? 
Select and explain. 
A. 0.5 - 0.8 ppm, B. 1.5 - 3 ppm, C. 76 ppm, D. None
A: 0.5 - 0.8 ppm
Answer: A: 0.5 - 0.8 ppm 
Explanation: The accepted safe level of fluoride in drinking water is 0.5 - 0.8 ppm. Deficiency of fluorine in drinking water is associated with dental caries and excess with dental and skeletal fluorosis.