**Core Concept**
Koebner phenomenon, also known as isomorphic response, refers to the appearance of skin lesions on lines of trauma in patients with pre-existing skin conditions such as psoriasis, vitiligo, or lichen planus. This phenomenon is thought to be an autoimmune response triggered by skin injury.

**Why the Correct Answer is Right**
The Koebner phenomenon is typically seen in conditions with a strong autoimmune component, such as psoriasis, vitiligo, and lichen planus. These conditions involve an abnormal immune response to skin injury, leading to the formation of new lesions along the lines of trauma. In contrast, conditions with a non-autoimmune or infectious etiology are less likely to exhibit the Koebner phenomenon.

**Why Each Wrong Option is Incorrect**
**Option A:** Psoriasis - Incorrect because psoriasis is a classic example of a condition that exhibits the Koebner phenomenon.
**Option B:** Vitiligo - Incorrect because vitiligo is another condition known to exhibit the Koebner phenomenon.
**Option C:** Lichen planus - Incorrect because lichen planus is also a condition that can exhibit the Koebner phenomenon.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize the Koebner phenomenon in patients with skin conditions, as it can help in the diagnosis and management of these conditions. A classic exam trap is to remember that conditions with a strong autoimmune component are more likely to exhibit this phenomenon.

**Correct Answer: D.**