**Core Concept**
Hassall’s corpuscles are specialized structures found in the thymus gland, composed of epithelial cells arranged in concentric layers. They play a key role in the maturation and selection of T-lymphocytes during immune development.

**Why the Correct Answer is Right**
Hassall’s corpuscles are located in the cortical region of the thymus, specifically within the medullary epithelial cells. These structures are involved in the negative selection of T-cells to prevent autoimmunity. They consist of layers of epithelial cells with a central core of concentrically arranged cells, and their presence is a hallmark of thymic tissue.

**Why Each Wrong Option is Incorrect**
Option B: Lymph nodes do not contain Hassall’s corpuscles; they house lymphoid follicles and germinal centers, not these specific epithelial structures.
Option C: The spleen contains red and white pulp but lacks Hassall’s corpuscles; it functions in filtration and immune surveillance, not T-cell maturation.
Option D: The liver is primarily involved in metabolism and detoxification, with no lymphoid structures like Hassall’s corpuscles.

**Clinical Pearl / High-Yield Fact**
Hassall’s corpuscles are only found in the thymus and are essential for proper T-cell education. Their absence or atrophy may be associated with impaired immune function, especially in immunodeficiency disorders.

✓ Correct Answer: A. Thymus