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
Mechanism of actions of montelukast is: 
Select and explain. 
A. Competitive antagonist of leukotriene receptors, B. Inhibits alpha receptor, C. Beta receptor agonist, D. Non-competitive inhibitor of leukotriene synthesis
A: Competitive antagonist of leukotriene receptors
Answer: A: Competitive antagonist of leukotriene receptors 
Explanation: None