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: Dental
[{'content': 'Of the light produced by quartz — tungsten -halogen, only a small percentage is suitable for curing composite resin material and most is converted into heat. How much percentage of this light is useful for curing? \nSelect and explain. \nA. 0.50%, B. 5%, C. 10%, D. 50%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]