A 72-year-old man with chronic kidney disease stage 4 (eGFR 20 mL/min/1.73 m²) presents with pruritus and fatigue. Labs show potassium 6.6 mmol/L with peaked T waves on ECG. What is the most appropriate immediate management step?AAdminister intravenous calcium gluconateBStart oral sodium polystyrene sulfonate onlyCSchedule urgent outpatient dialysisDIncrease dietary potassium restriction without medicationsEObserve and repeat potassium in 6 hoursCheck my answer