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': 'Deaths from lactic acidosis in diabetes mellitus is associated with therapy with which one of the following- \nSelect and explain. \nA. Metformin, B. Tolbutamide, C. Phenformin, D. Glipizide', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Phenformin", 'role': 'assistant'}]