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
Indomethacin can antagonize the diuretic action of loop diuretics by: 
Select and explain. 
A. Preventing prostaglandin mediated intrarenal-hemodynamic actions, B. Blocking the action in ascending limb of loop of Henle, C. Enhancing salt and water reabsorption in distal tubules, D. Increasing aldosterone secretion
A: Preventing prostaglandin mediated intrarenal-hemodynamic actions
Answer: A: Preventing prostaglandin mediated intrarenal-hemodynamic actions 
Explanation: Loop diuretics release PGs that induce intrarenal hemodynamic changes which secondarily affect salt output. Indomethacin and other NSAIDs inhibit the formation of PG. Therefore, NSAIDs blunt the action of loop diuretics.