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': 'False about guidelines on sanitary well \nSelect and explain. \nA. >15 m away from drinking water source, B. Minimum 20 feet depth, C. Parapet wall should > 20 cm above ground, D. Parapet wall should > 75 cm above ground', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]