Which of the following is a component of asthma?

Bronchoconstriction is a central feature of asthma and involves the tightening of the smooth muscles surrounding the airways, leading to a narrowing of these passages. In individuals with asthma, this bronchoconstriction occurs in response to various triggers, such as allergens, irritants, exercise, or respiratory infections. This narrowing results in difficulty breathing, wheezing, coughing, and a feeling of tightness in the chest as airflow is obstructed.

The other options present factors and conditions that are not primary components of asthma. Increased blood pressure is not typically associated directly with asthma as a component, whereas abnormal breathing patterns can be a consequence of the disease but are not a primary feature. Chest wall deformities are anatomical issues that may affect breathing but are not intrinsic components of asthma itself. Thus, bronchoconstriction stands out clearly as an essential aspect of the asthmatic process, underlying the obstructive nature of this condition.