This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
Recommended level of fluorides in drinking water in our country is accepted as - 
Select and explain. 
A. 0.5 mg/L, B. 1.5 mg/L, C. 2.5 mg/L, D. 3.5 mg/L
A: 0.5 mg/L
Answer: A: 0.5 mg/L 
Explanation: Fluorine is the most abundant element in nature. The recommended level of fluoride in drinking water in India is 0.5 to 0.8 mg/L. Excess of fluorides results in endemic fluorosis, skeletal and dental fluorosis. Inadequate levels of fluorine results in dental caries. Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 682