This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney Stones & Renal Tubular Acidosis, Subject name: Medicine
Best for management of a 3 cm stone in renal pelvis without evidence of hydronephrosis is? 
Select and explain. 
A. ESWL, B. PCNL, C. Antegrade Pyeloplasty, D. Retrograde pyeloplasty
B: PCNL
Answer: B: PCNL 
Explanation: ESWL- done for stone less than 2.5 cm size PCNL-if stone is > 2.5 cm will treat by PCNL Most common kidney stone =calcium oxalate Etiology=idiopathic hypercalciuria