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
[{'content': 'Leukotriene receptor antagonist used for bronchial asthma is : \nSelect and explain. \nA. Zafirlukast, B. Zileuton, C. Cromolyn sodium, D. Aminophylline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Montelukast, zafirlukast and pranlukast are Cys-LT1 receptor antagonists.\nZileuton inhibits the production of leukotrienes by inhibiting the enzyme 5-lipoxygenase.', 'role': 'assistant'}]