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: Ophthalmology
[{'content': 'The wavelength of laser (in nanometers) for shaping cornea in refractive surgery is - \nSelect and explain. \nA. 193 nm, B. 451 nm, C. 532 nm, D. 1064 nm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Corneal Reshaping precedures such as Photorefractive keratectomy (PRK) and Laser Assisted in Situ Keratomileusis (LASIK) are performed by lasers in the ultraviolet wavelength of 193 nm to 213 nm. The most commonly used laster for such procedures is the Argon Fluride Excimer Laser (ArF) with a length of 193 nm.', 'role': 'assistant'}]