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
Recommended illumination suggested by Illuminating Engineer Society for general office work: 
Select and explain. 
A. 100 lux, B. 400 lux, C. 900 lux, D. 2500 lux
B: 400 lux
Answer: B: 400 lux 
Explanation: Visual task Illumination (lux) Casual reading 100 General office work 400 Fine assembly 900 Watch making 2500 Ref: Park 21st edition, page 684. Chapter: Environment and health.