This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following is an adrenergic drug preferred for arresting labour? \nSelect and explain. \nA. Ritodrine, B. Isoprenaline, C. Salbutamol, D. Terbutaline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Ref: KDT 6/e p323) Isoxsuprine and ritodrine are selective b2 agonists useful as tocolytic agents for arresting labour. Pulmonary edema is an impoant adverse effect of these agents.', 'role': 'assistant'}]