**Core Concept**
Bronchial asthma is a chronic inflammatory disease of the airways characterized by recurring episodes of wheezing, shortness of breath, chest tightness, and coughing. The underlying pathophysiology involves airway hyperresponsiveness, inflammation, and remodelling.

**Why the Correct Answer is Right**
In bronchial asthma, the airway smooth muscle is sensitized and hyperresponsive to various stimuli, leading to bronchoconstriction. This is due to the release of mediators such as histamine, leukotrienes, and cytokines from mast cells, eosinophils, and T-lymphocytes. The airway epithelium is also damaged, leading to the loss of its protective barrier function and the release of pro-inflammatory signals.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be tempting, but bronchial asthma is not primarily characterized by airway obstruction due to excess mucus production.
**Option B:** While bronchial asthma involves inflammation, it is not primarily an autoimmune disease, unlike conditions such as rheumatoid arthritis.
**Option C:** This option might be relevant in the context of chronic obstructive pulmonary disease (COPD), but it is not a key feature of bronchial asthma.

**Clinical Pearl / High-Yield Fact**
One key feature of bronchial asthma is its reversibility, which is the hallmark of airway hyperresponsiveness. This means that symptoms can be alleviated with bronchodilators, and lung function can be improved with treatment.

**Correct Answer:** A.