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
Which of the following does not have a role in acute attack of asthma ? 
Select and explain. 
A. Cromolyn sodium, B. Ipratropium, C. Steroids, D. Salbutamol
A: Cromolyn sodium
Answer: A: Cromolyn sodium 
Explanation: None