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 drug is preferred in acute attack of asthma during labour \nSelect and explain. \nA. Salbutamol, B. Formeterol, C. Ipratropium, D. Zafirleukast', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ipratropium is a M3-antagonist used in acute attack of asthma during labour, as Beta 2-agonists are avoided because of tocolytic action.', 'role': 'assistant'}]