**Core Concept**
Buerger disease, also known as thromboangiitis obliterans, is a rare disorder characterized by inflammation and thrombosis of small and medium-sized arteries and veins. The disease predominantly affects young smokers, leading to ischemic symptoms in the limbs.

**Why the Correct Answer is Right**
The Buerger disease triad consists of three key components:
* **Ischemic pain**: This is a common presenting symptom, often described as severe, cramping pain in the affected limbs.
* **Ischemic ulcers**: These are characteristic skin lesions that develop as a result of inadequate blood supply to the skin.
* **Gangrene**: This is a severe complication of Buerger disease, resulting from prolonged ischemia and tissue necrosis.

**Why Each Wrong Option is Incorrect**
**Option A:**
Is not a part of the Buerger disease triad. While systemic hypertension can exacerbate the disease, it is not a defining characteristic of the triad.

**Option B:**
Is not accurate. While smoking is a significant risk factor for Buerger disease, it is not a component of the triad itself.

**Option C:**
Is not a part of the Buerger disease triad. While peripheral artery disease (PAD) shares some similarities with Buerger disease, they are distinct entities.

**Option D:**
Is not a part of the Buerger disease triad. While vasculitis can be a feature of Buerger disease, it is not a defining characteristic of the triad.

**Clinical Pearl / High-Yield Fact**
Buerger disease is strongly associated with smoking, and quitting is essential for disease management. Patients with Buerger disease often require aggressive smoking cessation and limb-salvage procedures.

**Correct Answer:**
None of the above options are correct components of the Buerger disease triad.