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': 'Helium-neon (HeNe) Lasers are example for \nSelect and explain. \nA. Excimer lasers, B. Gas lasers, C. Diode lasers, D. Solid state lasers', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]