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
The sulphonylurea with relative longer duration of action is: 
Select and explain. 
A. Chlorpropamide, B. Tolbutamide, C. Glibenclamide, D. Glipizide
A: Chlorpropamide
Answer: A: Chlorpropamide 
Explanation: The duration of action of various sulfonylureas is given below:
Tolbutamide: 6-8 hours
Glipizide: 10-16 hours
Glibenclamide: 16-24 hours
Chlorpropamide: 30-36 hours