**Core Concept**
Lupus erythematosus (LE) is a chronic autoimmune disease characterized by the production of autoantibodies against various components of the cell nucleus, resulting in inflammation and tissue damage. The exact pathogenesis of LE is multifactorial, involving genetic predisposition, environmental triggers, and dysregulation of the immune system.

**Why the Correct Answer is Right**
The correct answer involves the identification of the hallmark feature of LE, which is the production of autoantibodies against the nuclear antigens such as DNA, histones, and ribonucleoproteins. These autoantibodies activate the complement system, leading to the formation of immune complexes that deposit in various tissues, causing inflammation and tissue damage. The most commonly affected tissues include the skin, joints, kidneys, and nervous system.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not accurately describe the hallmark feature of LE.
**Option B:** Incorrect because it is more characteristic of rheumatoid arthritis, which is a different autoimmune disease.
**Option C:** Incorrect because it is more characteristic of Sjögren's syndrome, which is another autoimmune disease that primarily affects the exocrine glands.

**Clinical Pearl / High-Yield Fact**
The presence of antinuclear antibodies (ANA) is a sensitive but nonspecific marker for LE. A positive ANA test requires further evaluation to determine the clinical significance, as it can be present in various other autoimmune diseases and even in healthy individuals.

**Correct Answer: C. Systemic vasculitis.**