A 60-year-old woman is brought to emergency by her husband. She has a 20-year history of hypertension. Current medications include lisinopril, atorvastatin, and aspirin. They live on a farm. Serum studies show:
Calcium 9.5 mg/dL
Sodium 137 mEq/L
Potassium 4.0 mEq/L
Chloride 104 mEq/L
Bicarbonate 21 mEq/L
Which of the following is the most likely diagnosis?