Normal fluoride level in water:: (A) 2.0 mg/1, (B) 0.5 mg/1, (C) 1.5 mg/1, (D) 2.5 mg/1
Answer is B. Ref: 21st edition Park, pg 577 & pg 668Explanation:The major source of fluorine to man is drinking water.In most parts of India the fluoride content of drinking water is about 0.5 mg/L.The recommended maximum limit of concentration of fluoride is 1.5 mg/litre.