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': 'As compared to UV light, visible light can cure: \nSelect and explain. \nA. Greater depth of resin, B. Lesser depth of resin, C. Only superficial layer, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Although the polymerization reaction was under the direct control\xa0of the clinician, the inability of these short UV wavelengths to\xa0penetrate deeply into the resin composite meant that the incremental\xa0layers of resin could be at most 1 mm thick.\nBlue light can penetrate deeper into the resin than UV or\xa0violet light, such that some “blue light–cured” restorations can\xa0now be adequately light cured in increments that are up to 5-mm\xa0thick.\nPhillips Dental materials 12th edition pg no 174', 'role': 'assistant'}]