**Core Concept**
Cell-matrix adhesions, also known as focal adhesions, are complex structures that facilitate the interaction between cells and the extracellular matrix (ECM). They play a crucial role in cell migration, cell signaling, and tissue organization.

**Why the Correct Answer is Right**
Cell-matrix adhesions are primarily mediated by integrins, a family of transmembrane receptors that interact with ECM components such as collagen, laminin, and fibronectin. Integrins bind to these ECM molecules through their extracellular domain, while their cytoplasmic tail interacts with the cytoskeleton, specifically with actin and talin. This interaction triggers the recruitment of various signaling molecules, including focal adhesion kinase (FAK) and paxillin, which regulate cell migration, proliferation, and survival.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because integrins are the primary receptors involved in cell-matrix adhesions, not growth factor receptors.
**Option B:** This option is incorrect because cadherins are primarily involved in cell-cell adhesions, not cell-matrix adhesions.
**Option C:** This option is incorrect because selectins are primarily involved in leukocyte rolling and adhesion during inflammation, not cell-matrix adhesions.

**Clinical Pearl / High-Yield Fact**
Cell-matrix adhesions are critical for maintaining tissue integrity and facilitating wound healing. Disruptions in these adhesions have been implicated in various diseases, including cancer, fibrosis, and cardiovascular disease.

**Correct Answer: C. Integrins**