**Core Concept**
Vitreous humor is the clear, gel-like substance filling the center of the eyeball, providing structural support and maintaining the eye's spherical shape. It is composed of 98% water, 1% collagen, and 1% hyaluronic acid, with a unique structure that allows for flexibility and transparency.

**Why the Correct Answer is Right**
The correct answer is related to the unique composition and properties of vitreous humor. The correct answer highlights the importance of hyaluronic acid in maintaining the gel-like structure of vitreous humor. Hyaluronic acid is a polysaccharide that binds water molecules, creating a network of collagen fibers and maintaining the eye's shape. This unique composition allows vitreous humor to provide structural support and flexibility to the eye.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe a characteristic of vitreous humor. Vitreous humor is not primarily composed of glycerol.
**Option B:** This option is incorrect because it does not accurately describe a characteristic of vitreous humor. Vitreous humor is not primarily composed of sodium chloride.
**Option C:** This option is incorrect because it does not accurately describe a characteristic of vitreous humor. Vitreous humor is not primarily composed of cholesterol.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that vitreous humor is a unique substance that provides structural support and flexibility to the eye. Its composition and properties make it an essential component of maintaining the eye's spherical shape and allowing for clear vision.

**Correct Answer:** C.