This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Metformin is NOT effective in lowering of blood sugar level in which of the following patients? \nSelect and explain. \nA. Non diabetics, B. Obese diabetics, C. Type 2 diabetics, D. Diabetics not responding to sulfonylureas', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Ref:KDT 6/e p269) Metformin is the drug of choice for the treatment of obese diabetic patients, as it causes weight loss. It does not cause release of insulin, therefore less chances of hypoglycemia.', 'role': 'assistant'}]