**Core Concept**
The question tests the understanding of neutrophil granules, specifically the composition and function of secondary granules. Neutrophils contain various granules, including primary (azurophilic), secondary (specific), and tertiary granules, each with distinct functions and contents.

**Why the Correct Answer is Right**
Secondary granules in neutrophils are known for containing **lactoferrin**, **gelatinase**, and other enzymes that play a role in modulating inflammation and supporting the antimicrobial activity of neutrophils. These granules are also involved in the regulation of the oxidative burst and the release of antimicrobial peptides.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because primary granules, not secondary, contain **myeloperoxidase** and **defensins**.
**Option B:** This option is incorrect as it does not accurately describe the specific contents of secondary granules.
**Option C:** This option is also incorrect because tertiary granules have different functions and compositions compared to secondary granules.

**Clinical Pearl / High-Yield Fact**
Remember that secondary granules are crucial for the regulation of inflammation and the modulation of the immune response. Their dysfunction can lead to impaired neutrophil function and increased susceptibility to infections.

**Correct Answer:** D. Lactoferrin, gelatinase