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
[{'content': 'The drug not used in acute asthma is : \nSelect and explain. \nA. Salbutamol, B. Ipratropium, C. Montelukast, D. Hydrocortisone', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Only bronchodilator drugs are useful for the treatment of an acute attack of asthma. Main drugs are:\nBeta 2 agonists e.g. salbutamol, terbutaline\nAnticholinergics e.g. ipratropium, tiotropium\nMethylxanthines e.g. theophylline\nOther drugs used for asthma (like mast cell stabilizers, leukotriene receptor antagonists and lipoxygenase inhibitors) are indicated only for prophylaxis.', 'role': 'assistant'}]