Which among the following is a long acting beta-2 agonist?

The long-acting inhaled 2 agonists (LABA) salmeterol have proved to be a significant advance in asthma and COPD therapy. This drugs have a bronchodilator action of >12 hours and also protect against bronchoconstriction for a similar period. Albuterol is a sho acting selective 2 receptor agonist with pharmacological propeies and therapeutic indications similar to those of terbutaline. It is administered either by inhalation or orally for the symptomatic relief of bronchospasm. Pirbuterol is a sho acting and relatively selective 2 agonist. Its structure is identical to albuterol except for the substitution of a pyridine ring for the benzene ring. Pirbuterol acetate is available for inhalation therapy; dosing is typically every 4-6 hours. Pirbuterol is the only preparation available in a breath-activated meter-dose inhaler, a device meant to optimize medication delivery by releasing a spray of medication only on the patient's initiation of inspiration. Orciprenaline is a sho acting 2 adrenergic agonist.It is considered to be 2-selective, although it probably is less selective than albuterol or terbutaline and hence is more prone to cause cardiac stimulation. Ref: Westfall T.C., Westfall D.P. (2011). Chapter 12. Adrenergic Agonists and Antagonists. In L.L. Brunton, B.A. Chabner, B.C. Knollmann (Eds), Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e.