**Core Concept**
Phagocytosis is a cellular process in which a cell engulfs and digests foreign particles or microorganisms. It is an essential mechanism of the immune system, allowing cells like neutrophils and macrophages to eliminate pathogens and debris.

**Why the Correct Answer is Right**
Elie Metchnikoff, a Russian scientist, is credited with the discovery of phagocytosis. He observed that certain cells in starfish and frogs could engulf and digest bacteria, leading to a deeper understanding of the immune system. This discovery paved the way for further research into the mechanisms of phagocytosis and its role in human immunity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Elie Metchnikoff, not another scientist, discovered phagocytosis.
**Option B:** This option is incorrect because while Metchnikoff's work was groundbreaking, he did not discover phagocytosis independently; he built upon existing knowledge.
**Option C:** This option is incorrect because Metchnikoff's discovery of phagocytosis was a major breakthrough in immunology, but it was not a process he himself discovered.

**Clinical Pearl / High-Yield Fact**
Metchnikoff's work on phagocytosis led to a greater understanding of the immune system and the development of vaccines and immunotherapies. His discovery is a testament to the importance of basic scientific research in advancing medical knowledge.

**Correct Answer: C. Elie Metchnikoff**