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': 'Beta 2 agonist used in rescue therapy in acute respiratory conditions are all except? \nSelect and explain. \nA. Formoterol, B. Salbutamol, C. Bambuterol, D. Ketotifen', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Ketotifen Formoterol, Salbutomol and bambuterol are p 2 agonists. o Ketotifen is a mast cell stabilizer.", 'role': 'assistant'}]