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: Surgery
Which of the following lasers is used in the treatment of benign prostatic hyperplasia as well as urinary calculi? 
Select and explain. 
A. C02 laser, B. Excimer laser, C. Ho: YAG laser, D. Nd: YAG laser
C: Ho: YAG laser
Answer: C: Ho: YAG laser 
Explanation: Ho: YAG laser is used in the destruction of urinary tract stones and ablation of soft tissue in BPH. Holmium: YAG laser is the most common lithotripter for fragmenting urinary stones located in the ureter, kidney and bladder. In BPH, KTP laser vaporization is done in men with small to medium size prostate. Holmium laser enucleation is done in men with larger prostate. Ref: Lasers in Dermatology and Medicine By Keyvan Nouri, Pages 560-5.