Which of the following is not a test for diabetes mellitus

Answer is C (D-Xylose test): The D-Xylose test is a test for assessment of proximal small intestinal mucosa' fUnction. D- Xylose test is used to assess carbohydrate malabsorption and is not a test for assessment of Diabetes mellitus Fasting blood glucose, Random blood glucose and Oral Glucose Tolerance test are all used for assessment of diabetes mellitus. Criteria for the diagnosis of Diabetes Mellitus Symptoms of diabetes plus random blood glucose concentration 11.1 mmol/L (200 mg/dL) or Fasting plasma glucose 7.0 mmol/L (126 mg/dL) or Two-hour plasma glucose 11.1 mmol/L (200 mg/dL) during an oral glucose tolerance test.