This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Pharmacology
[{'content': 'A 28yr old female known case of asthma, on inhalational salbutamol, budesonide, and salmeterol. She complains of dyspnea. PEF is mildly improved. You have added zafirlukast to her prescription. What is the mechanism of action of zafirlukast? \nSelect and explain. \nA. Inhibition of actions of LTB4, B. Inhibition of actions of LTC4, D4, C. Inhibition of formation of LTC4, D4, D. Inhibition of release of Leukotrines from mast cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Montelukast and zafirlukast act by inhibiting the actions of slow reactive species (SRS-LTC4, D4)- Cysteine leukotriene receptor inhibitorsZileuton inhibits the formation of leukotrienes., Ref: Katzung 13th ed.Pg 350.', 'role': 'assistant'}]