A nurse is providing care for a client who has diabetes mellitus. Which of the following laboratory findings indicates the client most likely to be diagnosed with diabetic ketoacidosis (DKA)?

A. BUN 18 mg/dL Within normal range; not specific to DKA. B. Serum sodium 140 mg/dL Normal; not diagnostic of DKA. C. Arterial blood pH 7.46 Indicates alkalosis; DKA involves metabolic acidosis. D. Serum bicarbonate less than 15 Indicates metabolic acidosis, which is hallmark of DKA.