A 58-year-old woman with a 10-year history of hypertension and stage 3b chronic kidney disease secondary to diabetic nephropathy is started on lisinopril 10 mg daily. Her baseline creatinine was 2.8 mg/dL (eGFR 28 mL/min/1.73m²) and potassium was 4.2 mEq/L. She returns 2 weeks later reporting good tolerance with blood pressure 128/76 mmHg. Physical examination is unremarkable with no edema or jugular venous distension. Repeat laboratories show: Creatinine: 3.2 mg/dL Potassium: 5.8 mEq/L Bicarbonate: 22 mEq/L Urine output: maintained at baseline She denies dyspnea, chest pain, or decreased urine output. Which of the following is the most appropriate next action?

1. A)Discontinue lisinopril immediately due to acute kidney injury
2. B)Continue lisinopril; monitor potassium and renal function—expected initial changes with ACE inhibitors in advanced CKDGABARITO
3. C)Increase lisinopril to 20 mg daily to optimize renal protection
4. D)Switch to losartan for superior renal protective effects in diabetic nephropathy
5. E)Add hydrochlorothiazide to improve renal perfusion and lower potassium