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
[{'content': 'Potassium-sparing diuretics are all except: \nSelect and explain. \nA. Spironolactone, B. Triamterene, C. Amiloride, D. Ethacrynic acid', 'role': 'user'}, {'content': 'Answer: D \nExplanation: classification: High efficacy diuretics - Furosemide, Bumetanide, Torasemide Medium efficacy( inhibit Na-Cl sympo ) - Thiazides ( Hydrochlorothiazide, Benzthiazide, Hydroflumethiazide, Clopamide ), Thiazide-like (Indapamide, Xipamide, Metolazone) Carbonic anhydrase inhibitors - Acetazolamide Potassium-sparing - Spironolactone( Aldosterone antagonist), Amiloride, Triamterene ( inhibit renal epithelial Na channel ) Osmotic diuretics - Mannitol, Isosorbide, Glycerol ( Essentials of Medical Pharmacology, K.D Tripathi,6th edition, page 561 )', 'role': 'assistant'}]