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: Pharmacology
A 50–year old man has a history of frequent episodes of renal colic with high calcium renal stones. The most useful diuretic in the treatment of recurrent calcium stones is : 
Select and explain. 
A. Furosemide, B. Spironolactone, C. Hydrochlorothiazide, D. Acetazolamide
C: Hydrochlorothiazide
Answer: C: Hydrochlorothiazide 
Explanation: Thiazides cause hypercalcemia by decreasing the renal excretion of Ca2+. These are useful in a patient having hypercalciuria.
In such a patient, thiazides decrease the excretion of Ca2+ in the kidney and thus reduces the chances of stone formation.