You are answering a USMLE-style medical question. Question: A 70-year-old obese male presents to the emergency department with shortness of breath and cough of sudden onset. The patient states that his symptoms came on while he was sleeping. The patient has a past medical history of type II diabetes and is currently taking lisinopril, metformin, insulin, and fish oil. On physical exam, you note bipedal edema and jugular venous distention (JVD). An EKG and chest radiographs are obtained (Figures A and B). The patient is started on BIPAP and medical therapy and his symptoms improve rapidly. Lab values are as follows. Serum: Na+: 137 mEq/L K+: 3.2 mEq/L Cl-: 100 mEq/L HCO3-: 31 mEq/L BUN: 20 mg/dL Glucose: 120 mg/dL Creatinine: 1.2 mg/dL Ca2+: 10.9 mg/dL Which of the following is the best explanation of this patient's current presentation? Options: A) Furosemide B) Hydrochlorothiazide C) Renal tubular acidosis type II D) Renal tubular acidosis type IV Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.