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': '‘Safety officers’ have to be appointed in factories where no. of workers is more than \nSelect and explain. \nA. 500, B. 1000, C. 2000, D. 5000', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Health, Safety and Welfare recommendations:\n\nA minimum of 500 cubic feet space per worker\n1 Safety Officer per 1000 workers\n1 Welfare Officer per 500 workers\n1 Canteen for greater than 250 workers\n1 Crèche for greater than 30 women workers', 'role': 'assistant'}]