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': 'Venturi meter is used for- \nSelect and explain. \nA. Measuring amount required for chlorination, B. Measuring air velocity, C. Measuring bed strength in slow sand filter, D. Measuring dissolving capacity of gas', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Measuring bed strength in slow sand filter", 'role': 'assistant'}]