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
Purification of water at large scale is done by all except 
Select and explain. 
A. Disinfection of well, B. Rapid sand filter, C. Slow sand filter, D. Storage
A: Disinfection of well
Answer: A: Disinfection of well 
Explanation: Purification of water on a large scale Storage Filtration by slow sand or biological filters rapid sand or mechanical filters 3. Disinfection Purification of water on a small scale Household purification of water Disinfection of wells (refer pg:771 park 25th edition)