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': 'Recommended reflection factors include each of the following, except – \nSelect and explain. \nA. Ceilings 80%, B. Roofs 40%, C. Walls 50 to 60%, D. Furnitures 30 to 40%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]