**Core Concept**
Antigen-presenting cells (APCs) are a heterogeneous group of immune cells responsible for processing and presenting antigens to T-cells, thereby initiating an adaptive immune response. This process involves the recognition of antigens by pattern recognition receptors, such as Toll-like receptors (TLRs), and the subsequent activation of antigen processing and presentation pathways.

**Why the Correct Answer is Right**
Antigen-presenting cells include dendritic cells (DCs), macrophages, and B-cells, which all express major histocompatibility complex (MHC) class I and II molecules on their surface. These APCs engulf, process, and present antigens to T-cells through the MHC-peptide complex, facilitating the activation of T-cell responses.

**Why Each Wrong Option is Incorrect**
**Option A:** Not provided - skipping.
**Option B:** Not provided - skipping.
**Option C:** Not provided - skipping.
**Option D:** Not provided - skipping.

**Clinical Pearl / High-Yield Fact**
It's essential to note that while APCs are crucial for initiating T-cell responses, other immune cells, such as activated T-cells and neutrophils, can also present antigens to T-cells in certain contexts, although this is less efficient and less well-characterized.

**Correct Answer: D. Neutrophils**