**Core Concept**
The cornea is a complex, multi-layered structure composed of various types of epithelial cells, nerve fibers, and connective tissue. The outermost layer of the cornea, also known as the corneal epithelium, plays a crucial role in maintaining corneal transparency and function.

**Why the Correct Answer is Right**
The outer epithelium of the cornea is derived from the surface ectoderm, a group of cells that give rise to the outermost layer of the eye and skin. During embryonic development, the surface ectoderm invaginates to form the lens pit, and the remaining ectoderm covers the anterior portion of the eye, eventually giving rise to the corneal epithelium. This process is critical for the formation of the cornea and the development of the eye.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the corneal stroma, not the outer epithelium, is derived from the mesenchyme, a group of cells that give rise to connective tissue.
* **Option B:** This option is incorrect because the corneal endothelium, a single layer of cells on the posterior surface of the cornea, is derived from the neuroectoderm, not the surface ectoderm.
* **Option D:** This option is incorrect because the conjunctiva, a mucous membrane covering the inner surface of the eyelids and the outer surface of the eyeball, is derived from the surface ectoderm, but it is not the same as the corneal epithelium.

**Clinical Pearl / High-Yield Fact**
The corneal epithelium is a highly regenerative tissue that can repair itself within 24-48 hours after injury. This is due to the presence of stem cells in the limbal region, which serve as a reservoir for corneal epithelial cells.

**Correct Answer:** C.