This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
[{'content': 'Diabetes mellitis diagnosed when - \nSelect and explain. \nA. Fasting blood glucose is 100 and post prandial 140, B. Fasting blood sugar 125 and 2 hour postprandial blood sugar is 199, C. Insulin level......, D. HbA1c > 6.5%', 'role': 'user'}, {'content': "Answer: D \nExplanation: Criteria for the diagnosis of Diabetes mellitus : * Symptoms of diabetes plus random blood glucose concentration >=11.1 mmol/L (200 mg/dL)a or * Fasting plasma glucose >=7.0 mmol/L (126 mg/dL)b or * Hemoglobin A1c >= 6.5%c or * 2-h plasma glucose >= 11.1 mmol/L (200 mg/dL) during an oral glucose tolerance test Reference : page 2401 Harrison's Principles of Internal Medicine 19th edition", 'role': 'assistant'}]