**Core Concept**
Neurofibrillary tangles (NFTs) are a hallmark of Alzheimer's disease, composed of hyperphosphorylated tau protein. They disrupt neuronal function and contribute to cognitive decline. Understanding the regional vulnerability to NFTs is crucial in grasping the disease's pathophysiology.

**Why the Correct Answer is Right**
The lateral geniculate body (LGB) is the thalamic structure responsible for processing visual information from the retina. It is relatively spared in Alzheimer's disease due to its unique neuronal composition and lack of significant tau pathology. In contrast, other areas, such as the entorhinal cortex and hippocampus, are heavily affected by NFTs. The LGB's resistance to NFTs may be attributed to its lower expression of tau protein and its distinct neuronal connectivity patterns.

**Why Each Wrong Option is Incorrect**
**Option A:** The entorhinal cortex is a critical region for the formation and retrieval of memories, and it is one of the earliest areas affected by neurofibrillary tangles in Alzheimer's disease.

**Option B:** The hippocampus and temporal lobe are also heavily involved in Alzheimer's disease, with significant deposition of neurofibrillary tangles and amyloid plaques, leading to memory impairments.

**Option D:** The visual association areas, responsible for higher-order visual processing, are not specifically spared in Alzheimer's disease and can exhibit neurofibrillary tangle pathology.

**Clinical Pearl / High-Yield Fact**
In Alzheimer's disease, the degree of neurofibrillary tangle pathology correlates with cognitive decline, particularly in the hippocampus and entorhinal cortex. The relative sparing of the lateral geniculate body highlights the complex regional variability in tau pathology.

**✓ Correct Answer: C. Lateral Geniculate Body**