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': 'All of the following are essential for a well to meet the criteria of a sanitary well, EXCEPT: \nSelect and explain. \nA. Located at least 15m away from possible sources of contamination, B. Consumer responsibility, C. No user should have to carry water more than 500 metres, D. A parapet wall up to a height of at least 70-75cm', 'role': 'user'}, {'content': "Answer: C \nExplanation: The criteria for a sanitary well are: Location: It should be at least 15m away from possible sources of contamination located a higher level than nearby sources of contamination and no user should have to carry water for more than 100m Lining: The inside of the well should be lined with bricks up to a depth of 6 metre and 60-90cm above the ground level. Parapet wall should be up to a height of at least 70-75cm. Platform: A cement concrete platform should be constructed around the well with a radius of at least 1m in all directions. Drain Cover Hand pump Consumer responsibility Quality: The physical chemical and biological parameters of the well water should conform to acceptable standards Ref: Environment and health Park's textbook of Preventive and Social Medicine, 21st edition, page-656.", 'role': 'assistant'}]