**Core Concept**
Neutrophils are a type of white blood cell that plays a crucial role in the innate immune response, particularly in combating bacterial infections. They secrete various substances that help in phagocytosis, chemotaxis, and the modulation of the inflammatory response.

**Why the Correct Answer is Right**
Neutrophils secrete granules that contain enzymes and antimicrobial peptides, including defensins and cathelicidins. These substances help in the killing of bacteria and the modulation of the inflammatory response. The primary granules of neutrophils contain enzymes such as myeloperoxidase and lysozyme, which are involved in the breakdown of bacterial cell walls. The secondary granules contain chemokines and cytokines that help in the recruitment of other immune cells to the site of infection.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not listed.
* **Option B:** This option is not listed.
* **Option C:** This option is not listed.

**Clinical Pearl / High-Yield Fact**
Neutrophils are the most abundant type of white blood cell and play a crucial role in the initial response to bacterial infections. The secretion of granules by neutrophils helps in the modulation of the inflammatory response and the killing of bacteria.

**Correct Answer:** D.