Which of the following is a symptom of cystic fibrosis?

Bronchitis is indeed a symptom associated with cystic fibrosis. This condition leads to thick and sticky mucus production in the lungs, which increases the risk of lung infections and inflammation, contributing to chronic bronchitis. The buildup of mucus also obstructs airflow and can lead to recurrent respiratory problems, making individuals more susceptible to infections and chronic coughing.

While cystic fibrosis may indirectly be associated with issues like shortness of breath due to lung involvement, bronchitis specifically highlights the ongoing respiratory complications commonly seen in patients with cystic fibrosis. The other options, such as increased blood pressure and frequent headaches, are not direct or primary symptoms of the disease and thus do not provide an accurate representation of the condition's impact.