**Core Concept**
Rhinophyma is a type of skin condition characterized by a large, red, bumpy nose. It is a form of rosacea, a chronic cutaneous disorder that affects the face. Rhinophyma is often associated with excessive oil production and inflammation of the skin.

**Why the Correct Answer is Right**
Rhinophyma is primarily caused by the enlargement of sebaceous glands in the nose, leading to an overproduction of sebum. This results in inflammation, acne-like lesions, and the characteristic bulbous appearance of the nose. The condition is often linked to an imbalance of the skin's natural bacteria, as well as genetic predisposition.

**Why Each Wrong Option is Incorrect**
**Option A:** Rosacea is a precursor to rhinophyma, but it is not the primary cause. Rosacea is a broader category of skin conditions that can include rhinophyma, but rhinophyma is a specific manifestation.
**Option B:** Acne vulgaris is a different skin condition that can cause inflammation and lesions, but it is not directly linked to the development of rhinophyma.
**Option C:** Seborrheic dermatitis is a skin condition characterized by inflammation and flaking skin, but it is not the primary cause of rhinophyma.

**Clinical Pearl / High-Yield Fact**
Rhinophyma is often associated with telangiectasia, a condition characterized by dilated blood vessels near the surface of the skin. This can lead to the characteristic red appearance of the nose.

**Correct Answer:** C. Overgrowth of sebaceous glands.