A 65-year-old patient is admitted to the hospital with complaints of decreased urine output, fatigue, and swelling in the legs. Which of the following clinical cues is most indicative of acute kidney injury?

A. Hyperglycemia: Elevated blood glucose can occur with diabetes or stress responses but is not a specific indicator of acute kidney injury (AKI). It may be a contributing factor but not a diagnostic cue. B. Elevated serum creatinine levels: A rise in serum creatinine is a hallmark sign of AKI. Normal values range from 0.6 to 1.2 mg/dL. Increased levels indicate impaired glomerular filtration and reduced kidney function. C. Increased urine output: AKI often begins with an oliguric phase (urine output <400 mL/day). Increased urine output is more consistent with the recovery or diuretic phase, not with early AKI. D. Increased appetite: Appetite typically decreases in clients with AKI due to uremia and malaise. Increased appetite is not associated with impaired kidney function and is not a relevant diagnostic indicator.