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
[{'content': 'Drinking water is hest made free of cyclops by \nSelect and explain. \nA. Filtration, B. Boiling, C. Chlorination, D. None of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. is d i.e., None of the above "The most satisfactory and permanent method of controlling Cyclops in drinking water is to provide piped water supply or tube wells".', 'role': 'assistant'}]