**Core Concept**
Tertiary vitreous is a part of the eye's vitreous humor, which is a clear gel-like substance that fills the space between the lens and the retina. The vitreous humor is composed of two main parts: the primary vitreous, which forms during embryonic development, and the secondary and tertiary vitreous, which form after birth.

**Why the Correct Answer is Right**
The tertiary vitreous is a fibrovascular tissue that forms from the contraction of the hyaloid vessels. It is characterized by the presence of collagen and hyaluronic acid, which give it a gel-like consistency. The tertiary vitreous is more compact and less gel-like than the primary vitreous, and it plays a crucial role in maintaining the shape of the eyeball and providing support to the retina.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is incorrect because the primary vitreous is the first part of the vitreous humor to form during embryonic development, whereas the tertiary vitreous forms after birth.

**Option B:**
This option is incorrect because the secondary vitreous is a transitional stage in the development of the vitreous humor, and it is not the same as the tertiary vitreous.

**Option D:**
This option is incorrect because the vitreous body is the entire gel-like substance that fills the space between the lens and the retina, whereas the tertiary vitreous is a specific part of the vitreous body.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the vitreous humor plays a crucial role in maintaining the shape of the eyeball and providing support to the retina. Any changes in the vitreous humor, such as those that occur in vitreous detachment, can lead to vision problems and other complications.

**Correct Answer:** C.