What condition is characterized as an infection of the bronchi?

Bronchitis is specifically defined as the inflammation of the bronchi, which are the large air passages that lead from the trachea (windpipe) to the lungs. This condition is typically caused by an infection, most commonly viral, although bacteria can also be responsible. The inflammation results in symptoms such as coughing, production of mucus, wheezing, and difficulty breathing.

The other conditions listed do not involve the bronchi. Bronchiolitis pertains to inflammation of the smaller air passages called bronchioles, typically affecting infants and young children. Cellulitis is a bacterial skin infection that affects the subcutaneous tissues, whereas conjunctivitis refers to an inflammation of the conjunctiva of the eye, often associated with infection or allergies. Given that bronchitis is directly associated with an infection of the bronchi, it is the correct choice in this context.