This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': '2nd generation sulfonylurea drugs are all except: \nSelect and explain. \nA. Glipizide, B. Gliclazide, C. Tolbutamide, D. Glibenclamide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]