**Core Concept**
Granulation tissue is a type of connective tissue that forms during the healing process of wounds. It is a key component of the inflammatory phase of wound healing, characterized by the growth of new capillaries, fibroblasts, and inflammatory cells.

**Why the Correct Answer is Right**
Granulation tissue is composed of a mixture of cells, including fibroblasts, endothelial cells, inflammatory cells, and new capillaries. The fibroblasts in granulation tissue produce collagen and other extracellular matrix components, which contribute to the wound's strength and stability. The endothelial cells form new capillaries, which provide oxygen and nutrients to the healing tissue. Inflammatory cells, such as macrophages and lymphocytes, play a crucial role in removing debris and bacteria from the wound site.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because granulation tissue does not primarily consist of keratinocytes, which are the main cell type found in the epidermis.
**Option B:** This option is incorrect because scar tissue is a type of fibrotic tissue that forms after the inflammatory phase of wound healing, whereas granulation tissue is a key component of the inflammatory phase itself.
**Option C:** This option is incorrect because collagen is a component of granulation tissue, but it is not the primary cell type found in this tissue.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize that granulation tissue is a dynamic and highly vascularized tissue that plays a critical role in the wound healing process. The presence of granulation tissue indicates that the wound is progressing through the inflammatory phase and is on its way to healing.

**Correct Answer:** C. Fibroblasts, endothelial cells, inflammatory cells, and new capillaries.