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': 'Mechanism of actions of montelukast is: \nSelect and explain. \nA. Competitive antagonist of leukotriene receptors, B. Inhibits alpha receptor, C. Beta receptor agonist, D. Non-competitive inhibitor of leukotriene synthesis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]