Which condition is characterized by inflammation and hypersecretion of mucus in the bronchi?

The condition characterized by inflammation and hypersecretion of mucus in the bronchi is bronchitis. In bronchitis, the air passages become inflamed, often as a result of infection or exposure to irritants such as tobacco smoke or pollution. This inflammation leads to an increase in mucus production, which can obstruct airflow and cause symptoms like coughing, wheezing, and production of sputum.

In contrast, asthma is primarily a reactive airway disease, where the bronchi become narrowed due to muscle constriction, leading to difficulty breathing, but it is not defined by mucus hypersecretion alone. Pneumonia refers to an infection of the lung tissue, which can lead to fluid accumulation in the alveoli rather than increased mucus in the bronchi specifically. Emphysema is a form of chronic obstructive pulmonary disease (COPD) characterized by alveolar destruction, reduced elasticity, and air trapping, but it does not primarily involve inflammation and mucus overproduction in the bronchi.

Thus, bronchitis is distinctly defined by these symptoms, making it the correct choice for the question.