A nurse is reviewing laboratory findings for four clients. Which of the following clients has manifestations of acute kidney injury?

Rationale: A. A serum creatinine level of 6 mg/dL is significantly elevated above the normal range (0.6–1.3 mg/dL) and is a key indicator of acute kidney injury (AKI). Creatinine rises when the kidneys cannot effectively filter waste products from the blood, reflecting a reduction in glomerular filtration rate (GFR). This finding strongly suggests impaired renal function. B. A serum potassium of 4.5 mEq/L is within the normal range (3.5–5.0 mEq/L) and does not indicate AKI. In kidney injury, potassium is typically elevated due to reduced excretion. C. A hemoglobin level of 16 g/dL is within the normal range (13–17 g/dL for males, 12–15 g/dL for females) and is unrelated to AKI. D. A BUN level of 15 mg/dL is normal (reference range 7–20 mg/dL) and does not suggest kidney dysfunction.