**Core Concept**
Oxygen-dependent killing refers to the process by which certain cells, particularly neutrophils and macrophages, utilize oxygen to generate reactive oxygen species (ROS) that facilitate the killing of ingested microbes. This process is crucial in the innate immune response, particularly against intracellular pathogens.

**Why the Correct Answer is Right**
The correct answer involves the enzyme NADPH oxidase, which catalyzes the transfer of electrons to oxygen, resulting in the formation of superoxide anions (O2-). These superoxide anions are then converted to hydrogen peroxide (H2O2) and finally to hydroxyl radicals (•OH) through the action of the enzyme superoxide dismutase and myeloperoxidase, respectively. The resulting ROS are toxic to the ingested microbes and facilitate their killing.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately describe the process of oxygen-dependent killing.
* **Option B:** This option is incorrect because it refers to a different mechanism of action, specifically the killing of microbes through the action of antimicrobial peptides.
* **Option C:** This option is incorrect because it refers to a different process, specifically the killing of microbes through the action of complement proteins.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that oxygen-dependent killing is a critical mechanism of action for neutrophils and macrophages in the innate immune response, particularly against intracellular pathogens.

**Correct Answer:** C.