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
Acetazolamide is 
Select and explain. 
A. Competitive and reversible carbonic anhydrase inhibitor, B. Non-competitive and reversible carbonic anhydrase inhibitor, C. Competitive and irreversible carbonic anhydrase inhibitor, D. Non-competitive and irreversible carbonic anhydrase inhibitor
B: Non-competitive and reversible carbonic anhydrase inhibitor
Answer: B: Non-competitive and reversible carbonic anhydrase inhibitor 
Explanation: Carbonic anhydrase inhibitor act by non-competitive but reversible inhibition of the enzyme. Examples include acetazolamide,dorazolamide and brinzolamide.