Registered Dietitian

Answer: C - The lab test which is most useful for evaluating long-term blood sugar control in diabetics is the HbA1c test, which measures the percentage of hemoglobin in the blood that has glucose bound to it. Long periods of elevated blood glucose are associated with increasing levels of HbA1c. Two-hour post-prandial blood glucose and random non-fasting blood glucose levels do not provide information about long-term blood sugar control.