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
Which of the following is a long acting β2 selective agonist ? 
Select and explain. 
A. Formoterol, B. Isoprenaline, C. Salbutamol, D. Ephedrine
A: Formoterol
Answer: A: Formoterol 
Explanation: None