**Core Concept**
Phagocytosis is a vital cellular process by which certain cells of the immune system engulf and devour foreign particles, bacteria, dead cells, and other debris. It is a key mechanism in the body's defense against infection and inflammation.

**Why the Correct Answer is Right**
The correct answer is associated with the process of phagocytosis, which involves the extension of pseudopodia to surround the target particle, followed by the fusion of the cell membrane and the engulfment of the particle. This process is mediated by receptors such as Fc receptors and complement receptors on the surface of phagocytic cells, which bind to specific ligands on the target particle. The engulfed particle is then enclosed in a phagosome, which eventually fuses with a lysosome to form a phagolysosome, where the particle is degraded by enzymes.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while neutrophils are granulocytes, they are primarily involved in acute inflammation and are not the primary phagocytic cells in the body.

**Option B:** This option is incorrect because while macrophages are phagocytic cells, they are not the only cells capable of phagocytosis.

**Option C:** This option is incorrect because while epithelial cells can perform phagocytosis, it is not their primary function.

**Clinical Pearl / High-Yield Fact**
The process of phagocytosis is crucial in the body's defense against infection, and dysfunction of phagocytic cells can lead to increased susceptibility to infections. For example, individuals with chronic granulomatous disease (CGD) have impaired phagocytic function due to defects in the NADPH oxidase complex, leading to recurrent infections.

**Correct Answer: B. Macrophages. Macrophages.**