This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Pharmacology
Both loop diuretics and thiazides can cause hypokalemia by: 
Select and explain. 
A. Inhibiting proximal tubular K+reabsorption, B. Inhibiting Na+-K+-2Cl-cotranspo in the ascending limb of loop of Henle, C. Increasing the availability of Na+in the distal tubular fluid to exchange with interstitial K+, D. Potentiating the action of aldosterone
C: Increasing the availability of Na+in the distal tubular fluid to exchange with interstitial K+
Answer: C: Increasing the availability of Na+in the distal tubular fluid to exchange with interstitial K+ 
Explanation: Diuretics prevent the reabsorption of Na+-more amount of Na+ reaches the distal poion of the nephron i.e. late DT and collecting ducts. Na+ is exchanged with K+ and H+ Increased distal delivery of Na+ results in more exchange and thus hypokalemia