**Core Concept:** Bronchial asthma is a chronic respiratory disease characterized by airway inflammation and hyperresponsiveness. Mucus plugs in asthma can present as Whorls of shed epithelium, which is a specific morphological feature used for diagnosis and differentiating from other conditions.

**Why the Correct Answer is Right:** The correct answer, **C. Whorls of shed epithelium**, represents the unique morphological feature seen in bronchial asthma. These whorls are aggregates of epithelial cells that form in the airway mucus plugs due to the increased production and secretion of mucus. This response occurs as a result of airway inflammation and hyperresponsiveness in asthma, leading to the characteristic appearance of whorls in the mucus plugs.

**Why Each Wrong Option is Incorrect:**

A. **Squamous cell plugs:** This option refers to mucus plugs composed of squamous epithelial cells, which is not specific to asthma and can be seen in other conditions like chronic bronchitis.

B. **Circumferential mucus plugs:** This option describes mucus plugs that encircle the airway, which is not the specific feature of bronchial asthma. Circumferential plugs can be seen in other conditions like chronic bronchitis or cystic fibrosis.

D. **Mucus plugs without epithelial cells:** This option incorrectly suggests that asthma mucus plugs lack epithelial cells. In fact, the presence of epithelial cells in mucus plugs is a key feature of asthma.

**Clinical Pearl:** The identification of whorls of shed epithelium in mucus plugs is crucial for the accurate diagnosis of asthma, as it helps differentiate it from other conditions with similar mucus plugs (e.g., chronic bronchitis, cystic fibrosis) and ensures appropriate treatment for patients with asthma.