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
The leukotriene receptor antagonist used in bronchial asthma is - 
Select and explain. 
A. Zafirleukast, B. Zileuton, C. Ketotifen, D. Nedocromil
A: Zafirleukast
Answer: A: Zafirleukast 
Explanation: Ans. is 'a' i.e., Zafirleukast