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: Medicine
[{'content': 'A normal-anion-gap metabolic acidosis occurs in patients with - \nSelect and explain. \nA. Diarrhoea, B. Diabetic ketoacidosis, C. Methyl alcohol poisoning, D. Acute renal failure', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Causes of Non-Anion Gap Acidosis \nI Gastrointestinal bicarbonate loss\n\nDiarrhea\nExternal pancreatic or small-bowel drainage\nUreterosigmoidostomy, jejunal loop, ileal loop\nDrugs\n\n1. Calcium chloride (acidifying agent)\n\n\nMagnesium sulfate (diarrhea)\nCholestyramine (bile acid diarrhea)\n\nII. Renal acidosis\nA. Hypokalemia\n\nProximal RTA (type 2)\nDistal (classic) RTA type 1)\n\nB. Hyperkalemia\n1. Generalized distal nephron dysfunction (type 4 RTA)\n\nMineralocorticoid deficiency\nMineralocorticoid resistance\nNa+ delivery to distal nephron\nTubulointerstitial disease\nAmmonium excretion defect\n\nIII. Drug-induced hyperkalemia (with renal insufficiency)\n\nPotassium-sparing diuretics (amiloride, triamterene, spironolactone)\nTrimethoprim\nPentamidine\nAngiotensin-converting enzyme inhibitors and AT-II receptor blocker.\nNonsteroidal anti-inflammatory drugs\nCyclosporine\n\nIV Other\nA. Acid loads (ammonium chloride, hyperalimentation)\nB. Loss of potential bicarbonate: ketosis with ketone excretion\nC. Expansion acidosis (rapid saline administration)\nD. Hippurate\nE. Cation exchange resins.', 'role': 'assistant'}]