**Core Concept**
Type I collagen is the primary component of the corneal stroma, providing the structural framework and transparency necessary for vision. The cornea's unique composition and organization allow it to refract light efficiently.

**Why the Correct Answer is Right**
The correct answer is Type I collagen due to its high tensile strength and ability to maintain the cornea's shape. Type I collagen fibrils are arranged in a precise, hexagonal pattern in the corneal stroma, allowing for optimal light transmission and minimal scattering. This precise arrangement is critical for maintaining the cornea's transparency and refractive properties.

**Why Each Wrong Option is Incorrect**
**Option A:** Type II collagen is primarily found in cartilaginous tissues, such as the intervertebral discs and articular cartilage, and is not a major component of the cornea.

**Option B:** Type III collagen is often found in association with elastic fibers and is commonly seen in organs that are subject to mechanical stress, such as the aorta and the gut. It is not a primary component of the cornea.

**Option C:** Type IV collagen forms a sheet-like structure and is primarily found in the basement membranes of various tissues, including the glomerular basement membrane in the kidneys and the lamina densa of the dermal-epidermal junction. It is not a major component of the cornea.

**Clinical Pearl / High-Yield Fact**
The cornea's unique composition and organization make it an ideal candidate for corneal transplantation, which can restore vision in patients with corneal disease.

**Correct Answer: C. Type I collagen.**