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
Laser used in LASIK ? 
Select and explain. 
A. Yag, B. Diode, C. Excimer, D. None
C: Excimer
Answer: C: Excimer 
Explanation: Ans. is 'c' i.e., Excimer 3 PRK, PTK, LASIK and LASEK use excimer (argon fluoride) laser.