What respiratory condition might be triggered by pollen?

Asthma is a respiratory condition characterized by inflammation and narrowing of the airways, which can lead to difficulty breathing, wheezing, coughing, and chest tightness. Pollen, especially during certain seasons, can act as an allergen, triggering asthma symptoms in individuals who are sensitive to it. When pollen enters the respiratory system, it can cause an immune response that leads to inflammation in the airways, resulting in increased symptoms for those with asthma.

While conditions like sinusitis, pneumonia, and rhinitis also relate to the respiratory system, they have different underlying mechanisms or triggers. Sinusitis involves the inflammation of the sinuses and is often caused by infections or allergies but is not primarily triggered by pollen. Pneumonia is usually caused by infections (viral, bacterial, or fungal) rather than allergens like pollen. Rhinitis, while also related to allergens including pollen, specifically refers to nasal inflammation and is often considered a more straightforward allergic response rather than the complex airway inflammation seen in asthma.

Therefore, the association of asthma with pollen as a trigger makes it the correct answer in this context.