This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'Recommended illumination range satisfactory vision is ---- foot candles \nSelect and explain. \nA. 15-20, B. 25-50, C. 51-75, D. 76-100', 'role': 'user'}, {'content': 'Answer: A \nExplanation: An illumination of 15-20 footcandles (1 foot-candle = 10.76 Lux) is accepted as a basic minimum for satisfactory vision.Park 23e pg: 739', 'role': 'assistant'}]