**Core Concept**
Chemoattractants are signaling molecules that induce movement or chemotaxis in responsive cells, often leading to their accumulation at the site of the signal. This process is crucial in various physiological and pathological conditions, such as wound healing, inflammation, and immune responses. Chemoattractants interact with specific receptors on the surface of responsive cells, triggering a signaling cascade that ultimately leads to the directed movement of these cells.

**Why the Correct Answer is Right**
The correct answer involves molecules that are known to induce chemotaxis in responsive cells. For example, **chemokines**, such as CXCL8 (IL-8), are potent chemoattractants for neutrophils and other granulocytes. These chemokines bind to specific receptors, like CXCR1 and CXCR2, on the surface of these cells, leading to the activation of downstream signaling pathways that result in cell migration. Other chemoattractants, such as **leukotriene B4** (LTB4), also play a role in recruiting neutrophils and other leukocytes to sites of inflammation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because, although it may be related to the immune response, it is not a chemoattractant.
**Option B:** This option is incorrect because, although it is involved in the immune response, it is more of a cell adhesion molecule rather than a chemoattractant.
**Option C:** This option is incorrect because, although it has some chemotactic effects, it is primarily known for its role in cell proliferation and survival.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that chemoattractants play a crucial role in the recruitment of immune cells to sites of inflammation, which is a key aspect of the innate immune response. Understanding the mechanisms of chemoattraction is essential for appreciating the pathophysiology of various inflammatory conditions.

**Correct Answer: C. LTB4**