This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Asthma, Subject name: Pharmacology
Which of the following is a long acting bronchodilator? 
Select and explain. 
A. Salbutamol, B. Terbutaline, C. Adrenaline, D. Formoterol
D: Formoterol
Answer: D: Formoterol 
Explanation: Beta-2 agonists are well known bronchodilators. This includes:#Salbutamol, Terbutaline, Formoterol, Salmeterol, Indacaterol, Albuterol etc.Among these agents, formoterol, salmeterol, Indacaterol are longer acting analogue and are preferred in prophylactic therapy of bronchial asthma and COPD.