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
Ketotifen is a: 
Select and explain. 
A. Leucotriene antagonist, B. Antibody against IgE, C. Mast cell stabilizer, D. Mucolytic & expectorant
C: Mast cell stabilizer
Answer: C: Mast cell stabilizer 
Explanation: Ketotifen and sodium cromoglycate prevent degranulation of mast cell.