Which of these is a combination inhaler for asthma?

The choice of Seretide as a combination inhaler for asthma is accurate because it contains two active ingredients: fluticasone propionate, which is a corticosteroid that helps to reduce inflammation in the airways, and salmeterol, a long-acting beta-agonist (LABA) that works to relax the airway muscles and improve airflow. This dual action makes Seretide effective in managing asthma symptoms and preventing exacerbations by addressing both the inflammatory and bronchial constriction components of the disease.

The other options do not serve as combination inhalers. Pulmicort, for example, contains only budesonide, which is a corticosteroid and does not have a bronchodilator component. Azithromycin is an antibiotic and does not relate to asthma inhalers. Flixotide, like Pulmicort, is solely a corticosteroid with no bronchodilator included. Thus, Seretide's unique formulation makes it specifically suitable as a combination inhaler for treating asthma.