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
Which of the following is an adrenergic drug preferred for arresting labour? 
Select and explain. 
A. Ritodrine, B. Isoprenaline, C. Salbutamol, D. Terbutaline
A: Ritodrine
Answer: A: Ritodrine 
Explanation: (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.