This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Ophthalmology
The wavelength of laser {in nanometers} for shaping cornea in refractive surgery is - 
Select and explain. 
A. 193 nm, B. 451 nm, C. 532 nm, D. 1064 nm
A: 193 nm
Answer: A: 193 nm 
Explanation: Excimer laser is used : wavelength 193nm Mechanism : photo ablation. Uses : PRK, PTK, LASIK