**Core Concept**
The question is testing the student's knowledge of the pathological features associated with Alzheimer's disease (AD), a progressive neurodegenerative disorder characterized by cognitive decline and memory loss. Neurofibrillary tangles (NFTs) are a hallmark of AD, composed of hyperphosphorylated tau protein.

**Why the Correct Answer is Right**
Neurofibrillary tangles are formed by the aggregation of tau protein, which is a microtubule-associated protein that plays a crucial role in maintaining the structure and stability of microtubules in neurons. In AD, tau protein becomes hyperphosphorylated, leading to its aggregation and the formation of NFTs. This process disrupts the normal function of microtubules, leading to neuronal dysfunction and death. The presence of NFTs is a diagnostic feature of AD, and they are often found in combination with amyloid plaques.

**Why Each Wrong Option is Incorrect**
* **Option A:** Amyloid plaques are a characteristic feature of Alzheimer's disease, but they are not directly related to neurofibrillary tangles.
* **Option B:** Lewy bodies are a hallmark of Parkinson's disease and dementia with Lewy bodies, and are composed of alpha-synuclein protein, not tau protein.
* **Option D:** Pick bodies are a characteristic feature of frontotemporal dementia, and are composed of tau protein, but are not typically found in combination with neurofibrillary tangles.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that neurofibrillary tangles are a diagnostic feature of Alzheimer's disease, and their presence, along with amyloid plaques, can help confirm the diagnosis. A key clinical correlation is that patients with Alzheimer's disease often exhibit cognitive decline, memory loss, and difficulty with speech and daily tasks, as described in the question.

**Correct Answer:** C.