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: Medicine
Mast cell stabilizer used in ronchial Asthma is 
Select and explain. 
A. Raloxifene, B. Ketotifen, C. Azelastin, D. Baclofen
B: Ketotifen
Answer: B: Ketotifen 
Explanation: None