A nurse is reviewing the laboratory results of a client who is at risk for developing diabetes mellitus. The nurse should recognize that which of the following results indicates the client meets the criteria for diagnosis of diabetes mellitus?

Rationale: A. 2 hr blood glucose 170 mg/dL: A 2-hour oral glucose tolerance test result ≥200 mg/dL indicates diabetes. A value of 170 mg/dL is elevated but falls into the impaired glucose tolerance (prediabetes) range, not diagnostic for diabetes. B. Casual blood glucose 180 mg/dL: A random (casual) glucose level ≥200 mg/dL, with symptoms of hyperglycemia, supports a diabetes diagnosis. A level of 180 mg/dL is elevated but does not meet diagnostic criteria. C. Fasting blood glucose 155 mg/dL: A fasting glucose ≥126 mg/dL on two occasions is diagnostic for diabetes. A value of 155 mg/dL exceeds the threshold and meets the criteria for diagnosis. D. HbA1c 5.5%: An HbA1c ≥6.5% is diagnostic for diabetes. A value of 5.5% is within the normal range, indicating no diabetes.