## Core Concept
Hodgkin's disease, also known as Hodgkin lymphoma, is a type of lymphoma characterized by the presence of specific types of cells. The hallmark of Hodgkin's disease is the **Reed-Sternberg cell**, a large, abnormal B lymphocyte. This cell is crucial for the diagnosis of Hodgkin lymphoma.

## Why the Correct Answer is Right
The correct answer, , refers to **Reed-Sternberg cells**. These are distinctive, large, often multinucleated cells that are considered the neoplastic cells of Hodgkin lymphoma. They are derived from B lymphocytes and play a central role in the pathogenesis of the disease. The presence of Reed-Sternberg cells is a diagnostic criterion for Hodgkin lymphoma.

## Why Each Wrong Option is Incorrect
* **Option A:** This option does not correspond to the correct answer and likely represents another type of cell not characteristic of Hodgkin's disease.
* **Option B:** Similarly, this option does not match the correct answer and could represent a different cell type seen in various other conditions.
* **Option D:** This option is also incorrect as it does not refer to Reed-Sternberg cells.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that the diagnosis of Hodgkin lymphoma often involves the identification of Reed-Sternberg cells in a background of a mixed inflammatory infiltrate. These cells are typically **CD15+** and **CD30+** on immunohistochemistry, which helps in their identification and differentiation from other types of lymphomas.

## Correct Answer Line
**Correct Answer: B. Reed-Sternberg cells.**