This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Asthma, Subject name: Pharmacology
Mechanism of zileuton: 
Select and explain. 
A. Cyclooxygenase inhibitor, B. 5-lipoxygenase inhibitor, C. Phosphodiesterase inhibitor, D. Mast cell degranulation
B: 5-lipoxygenase inhibitor
Answer: B: 5-lipoxygenase inhibitor 
Explanation: Ans. B. 5-lipoxygenase inhibitorZileuton is drug which inhibit the synthesis of leukotrienes as they are chemotactic and causes bronchoconstriction.