This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
True regarding acetazolamide is 
Select and explain. 
A. Irreversible inhibitor of carbonic anhydrase, B. Structural resemblance to sulfonamides, C. It decrease so potassium excretion, D. It cause metabolic alkalosis
B: Structural resemblance to sulfonamides
Answer: B: Structural resemblance to sulfonamides 
Explanation: Acetazolamide is non-competitive but reversible inhibitor of carbonic anhydrase It is a sulfonamide derivative It causes hypokalemia and metabolic acidosis.