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': 'Which of the following drugs CANNOT be administered by inhalation \nSelect and explain. \nA. Theophylline, B. Ipratropium bromide, C. Budesonide, D. Terbutaline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: β2\xa0agonists like salbutamol and terbutaline can be administered by inhalational route.\nIpratropium and tiotropium are inhalational anticholinergic agents.\nInhalational steroids include budesonide, fluticasone, beclomethasone and\xa0flunisolide.\nTheophylline is given by oral route and is not used by inhalational route.', 'role': 'assistant'}]