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': 'Criteria for drinking water quality recommended by WHO includes - \nSelect and explain. \nA. Colour < 15 TCU, B. pH 6.5-8.5, C. Chloride 200-600 mg/1, D. All', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'a' i.e., Colour < 15 TCU; 'b' i.e., pH 6.5-8.5; 'c' i.e., Chloride 200-600 mg/l", 'role': 'assistant'}]