This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Water, Subject name: Social & Preventive Medicine
Proposed guideline values for radioactivity in drinking water is: 
Select and explain. 
A. Gross alpha activity 0.5 Bq/L and gross beta activity 1.0 Bq/L, B. Gross alpha activity 1.0 Bq/L and gross beta activity 0.5 Bq/L, C. Gross alpha activity 5.0 Bq/L and gross beta activity 10.0 Bq/L, D. Gross alpha activity 10 Bq/L and gross beta activity 5.0 Bq/L
A: Gross alpha activity 0.5 Bq/L and gross beta activity 1.0 Bq/L
Answer: A: Gross alpha activity 0.5 Bq/L and gross beta activity 1.0 Bq/L 
Explanation: Gross alpha radiological activity < 0.5 Bq/litre (New guideline WHO). Gross beta radiological activity <1.0 Bq/litre (New guideline - WHO). Other Guidelines of drinking water quality in India: Colour = < 15 TCU Turbidity = < 1 NTU Hardness = < 100-300 mg/L pH = 6.5- 8.5 TDS = < 500 mg/L Fluorides = < 1ppm Nitrates = < 45 mg/d Nitrites = < 3 mg/ d