**Core Concept**
Atherosclerotic occlusive disease at the bifurcation of aorta, also known as Leriche syndrome, is a condition characterized by occlusion of the aortic bifurcation leading to decreased blood flow to the lower extremities. It is associated with a triad of symptoms: claudication, impotence, and decreased or absent pulse in the lower extremities.

**Why the Correct Answer is Right**
The correct answer is **Option A:** because it is not a typical symptom of Leriche syndrome. Leriche syndrome is primarily associated with decreased blood flow to the lower extremities, which manifests as claudication, impotence, and decreased or absent pulse. While some patients may experience pain in the lower back or buttocks, this is not a characteristic symptom of Leriche syndrome.

**Why Each Wrong Option is Incorrect**
**Option B:** is incorrect because impotence is a common symptom of Leriche syndrome due to decreased blood flow to the pelvic organs. **Option C:** is incorrect because decreased or absent pulse in the lower extremities is a hallmark symptom of Leriche syndrome. **Option D:** is incorrect because claudication is a typical symptom of Leriche syndrome, manifesting as pain or cramping in the lower extremities during walking or exercise.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Leriche syndrome is often associated with a triad of symptoms: claudication, impotence, and decreased or absent pulse in the lower extremities. A thorough physical examination and history-taking can help diagnose this condition.

**Correct Answer:** D. Claudication.