This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diabetes Mellitus, Subject name: Medicine
Which sulfonylurea drug has the highest insulinotropic potency? 
Select and explain. 
A. Glyburide, B. Glipizide, C. Glimepiride, D. Gliclazide
A: Glyburide
Answer: A: Glyburide 
Explanation: Sulfonylureas act on receptors in pancreatic beta cells resulting in closure of potassium cells. This results in depolarization of Beta cell and release of insulin. Glyburide has the highest affinity/ insulinotropic action while tolbutamide has least affinity.