The nurse prepares to teach four clients about diabetes mellitus. Which client has the greatest need for instructions? Reference Range: Glycosylated hemoglobin A1C (HbA1C) [good glycemic control: less than 10%] Random blood glucose [less than or equal to 200 mg/dL (less than 11.1 mmol/L] Postprandial glucose (1-hour gestational diabetes) [less than 140 mg/dL (less than 7.8 mmol/L)] Fasting blood glucose [70 to 110 mg/dL (less than 6.1 mmol/L)]