This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'The following Thiazide diuretic is active if the GFR is 30-40 mm Hg \nSelect and explain. \nA. Metolazone, B. Benzthiazide, C. Chlorothiazide, D. Chlohalidone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Although most thiazide diuretics lose their effectiveness in renal failure, metolazone remains active even when the glomerular filtration rate (GFR) is below 30-40 mL/min (moderate renal failure). This gives it a considerable advantage over other thiazide diuretics, since renal and hea failure often coexist and contribute to fluid retention(Refer: K. D. Tripathi&;s Essentials of Medical Pharmacology, 7th edition, pg no: 583)', 'role': 'assistant'}]