**Core Concept**
Astrocytes play a crucial role in the repair and scarring process of the central nervous system (CNS) following injury, such as a cerebral contusion. The activation of astrocytes leads to the formation of a glial scar, which acts as a physical barrier to prevent further damage and promote healing.

**Why the Correct Answer is Right**
Astrocytes are the primary glial cells in the CNS and are responsible for scar formation after injury. Upon activation, astrocytes undergo a process called astrogliosis, characterized by increased expression of glial fibrillary acidic protein (GFAP) and other astrocytic markers. This leads to the formation of a glial scar, which is composed of compacted astrocytic processes and extracellular matrix. The glial scar serves as a physical barrier to prevent further damage and promote healing by isolating the damaged area from surrounding healthy tissue.

**Why Each Wrong Option is Incorrect**
**Option A:** Oligodendrocytes are responsible for myelination in the CNS, but they do not play a primary role in scar formation.
**Option B:** Microglia are involved in the immune response and phagocytosis of debris in the CNS, but they are not the principal mediators of scar formation.
**Option C:** Neurons are the primary functional units of the CNS, but they are not directly involved in scar formation.

**Clinical Pearl / High-Yield Fact**
Astrocytes also play a crucial role in the blood-brain barrier, regulating the movement of ions, nutrients, and waste products across the endothelial cells that line blood vessels in the CNS.

**Correct Answer:** C. Astrocytes.