This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
[{'content': 'Confocal scanning laser ophthalmoscope uses \nSelect and explain. \nA. Infrared laser, B. Diode laser, C. Excimer laser, D. YAG laser', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Confocal scanning laser ophthalmoscope It is an instrument using a confocal laser system to provide and analyze a three-dimensional image of the optic nerve head, peripapillary retina, and macular region It uses a 670 nm diode laser and measures the amount of light reflected from a series of 16-64 sections in depth and reconstructs them to show the anatomy of the optic nerve head and reconstruct the anatomy of the retinal nerve fiber layer. Refer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 461 - 462', 'role': 'assistant'}]