## **Core Concept**
Neutrophils are a type of white blood cell and a crucial part of the innate immune system. They play a key role in defending against infections, particularly bacterial and fungal infections. Neutrophils exert their functions through various mechanisms, including phagocytosis and the release of granular contents.

## **Why the Correct Answer is Right**
Neutrophils secrete several substances that help in fighting infections. Among the options provided, the correct answer involves understanding what neutrophils release to perform their functions. Neutrophils are known to release **lysozyme**, an enzyme that breaks down bacterial cell walls, and other antimicrobial substances.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because, although it might relate to immune response, it is not specifically what neutrophils are known to secrete.
- **Option B:** This option is incorrect as it does not accurately represent a substance secreted by neutrophils.
- **Option C:** This option might relate to immune cells in general but is not specific to neutrophil secretion.
- **Option D:** This option is incorrect because it does not accurately describe a substance secreted by neutrophils.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that neutrophils play a critical role in acute inflammatory responses, especially against bacterial infections. Their granules contain enzymes and antimicrobial peptides, such as **defensins** and **cathepsins**, which help in killing ingested microbes.

## **Correct Answer:** .