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': 'Drug used for type I and type II Diabetes mellitus is- \nSelect and explain. \nA. Glipizide, B. Tolbutamide, C. Metformin, D. Insulin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Uses Of insulin in Diabetes Ref - researchgate.net', 'role': 'assistant'}]