You are answering a USMLE-style medical question. Question: A 62-year-old woman is evaluated because of a 3-day history of headache, nausea, and decreased urination. Laboratory studies show: Serum Na+ 136 mEq/L K+ 3.2 mEq/L Cl- 115 mEq/L Mg2+ 1.4 mEq/L Urine pH 7.0 Arterial blood gas analysis on room air shows a pH of 7.28 and a HCO3- concentration of 14 mEq/L. Prolonged treatment with which of the following drugs would best explain this patient's findings?" Options: A) Trimethoprim-sulfamethoxazole B) Eplerenone C) Amphotericin B D) Heparin Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.