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
All are true about sulphonyl ureas except? 
Select and explain. 
A. It blocks ATP sensitive K+ channels and increase insulin release, B. They have higher risk of causing hypoglycemia than meglitinides, C. They are used mainly in type 1 DM, D. Chlorpropamide can cause dilutional  hyponatremia
C: They are used mainly in type 1 DM
Answer: C: They are used mainly in type 1 DM 
Explanation: Sulphonyl ureas are mainly used in Type 2 DM because Type 1 DM is characterized by autoimmune destruction of β - cells of pancreas and atleast 30% of β - cells should be present for sulphonyl ureas to be effective.