**Core Concept**
Phagolysosomal-enzymatic digestion is a critical process in the immune response where phagocytic cells, such as neutrophils and macrophages, fuse with lysosomes to form phagolysosomes. This fusion enables the degradation of engulfed foreign particles, bacteria, and dead cells through enzymatic action.

**Why the Correct Answer is Right**
The correct answer is **Cathepsin D**. Cathepsin D is a lysosomal aspartic protease that plays a key role in the phagolysosomal-enzymatic digestion process. It is responsible for the hydrolysis of proteins, including bacterial enzymes and structural proteins, facilitating the breakdown of engulfed pathogens. The acidic pH of the lysosome activates Cathepsin D, allowing it to cleave peptide bonds and initiate protein degradation.

**Why Each Wrong Option is Incorrect**
**Option A:** **Lysosomal-associated membrane protein 1 (LAMP-1)** is a transmembrane protein that helps maintain lysosomal membrane integrity and is involved in the sorting of lysosomal proteins, but it is not directly responsible for phagolysosomal-enzymatic digestion.

**Option B:** **NADPH oxidase** is an enzyme complex that generates superoxides in the phagosome, contributing to the oxidative burst that kills ingested pathogens, but it is not directly involved in enzymatic digestion.

**Option C:** **Proteasome** is a complex that degrades proteins by proteolysis, but it is primarily found in the cytosol and is not directly involved in phagolysosomal-enzymatic digestion.

**Clinical Pearl / High-Yield Fact**
Cathepsin D's role in phagolysosomal-enzymatic digestion highlights the importance of the lysosome in the innate immune response. Dysfunction in lysosomal enzymes, such as Cathepsin D, has been implicated in various diseases, including lysosomal storage disorders and cancer.

**Correct Answer:** C. Cathepsin D.