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
Anti–diabetic effect of sulfonylureas is by reducing: 
Select and explain. 
A. Glucagon production, B. Insulin secretion, C. Tissue sensitivity to insulin, D. Tissue sensitivity to glycogen
A: Glucagon production
Answer: A: Glucagon production 
Explanation: None