Which diagnostic test for diabetes mellitus provides a measure of glucose levels for the previous 8 to 12 weeks?

A. Glycosylated hemoglobin (HbA1C): The HbA1C test provides an average measure of blood glucose levels over the past 8 to 12 weeks. It reflects the percentage of hemoglobin that has glucose attached to it, giving an indication of long-term blood sugar control. B. Oral glucose tolerance test: This test measures the body’s response to glucose by checking blood sugar levels after drinking a sugary solution. It does not provide an average of blood glucose over weeks, but rather, it assesses blood glucose levels at specific time points after glucose ingestion. C. Postprandial glucose test: This test measures blood glucose levels after eating a meal, typically 1 to 2 hours later. It provides information about immediate glucose levels, not long-term glucose control over weeks. D. Fasting blood sugar (FSBS): This test measures blood glucose levels after fasting for at least 8 hours. It gives a snapshot of current glucose levels but does not provide a measure of glucose control over weeks.