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
A child was given leukotriene receptor antagonist for prophylaxis of asthma. The drug is - 
Select and explain. 
A. Monteleukast, B. Zileuton, C. Nedocromil, D. Verpami I
A: Monteleukast
Answer: A: Monteleukast 
Explanation: Ans. is 'a' i.e., Monteleukast o Monteleukast and zafirleucast are cystenyl LT, (cys LT,) receptor antagonists.