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': 'Which of the following is considered an adequate water supply/head/day – \nSelect and explain. \nA. 50–150 L, B. 150–200 L, C. 200–250 L, D. 100–150 L', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]