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
Which of the following decreases effectiveness of insulin - 
Select and explain. 
A. Thiazide, B. Atropine, C. b-blockers, D. Acute alcohol ingestion
A: Thiazide
Answer: A: Thiazide 
Explanation: Ans. is 'a' i.e., Thiazide o Thiazide, furosamide, coicosteroids, oral contraceptives, salbutamol, nifedipine tend to raise blood sugar and reduce effectiveness of insulin.