Which combination of steroids and B2 agonists is delivered via DPI?

The combination of steroids and B2 agonists delivered via dry powder inhaler (DPI) is fluticasone and salmeterol. This formulation, commonly known as Advair, features fluticasone as the corticosteroid and salmeterol as the long-acting beta-agonist (LABA).

Inhaled corticosteroids, like fluticasone, are used to reduce inflammation in the airways, while LABAs such as salmeterol provide bronchodilation by relaxing the smooth muscles in the airway, making it easier for patients to breathe. The DPI delivery system allows for patient-friendly administration, where the medication is inhaled in a powdered form, requiring less coordination than nebulizers or metered-dose inhalers.

The other combinations mentioned are not delivered via DPI or are not associated with that delivery method. Some of these may be available in different forms, like metered-dose inhalers or nebulizers, but fluticasone combined with salmeterol specifically targets DPI delivery, making this combination the correct answer in the context of the question.