**Core Concept**
The notochord is a flexible, rod-like structure that forms the precursor to the vertebral column during embryonic development. It is a crucial component of the embryonic mesoderm, which eventually gives rise to the vertebral column, intervertebral discs, and other associated structures.

**Why the Correct Answer is Right**
The remnant of the notochord in adults is the nucleus pulposus, which is the gelatinous center of the intervertebral discs. This is because the notochord degenerates and transforms into the intervertebral discs during embryonic development, with the nucleus pulposus retaining the characteristics of the notochordal cells. The nucleus pulposus is rich in proteoglycans and water, giving it a gel-like consistency that allows it to act as a shock absorber in the spine.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the annulus fibrosus, the outer layer of the intervertebral disc, is not derived from the notochord. Instead, it is formed from the mesoderm that surrounds the notochord.
**Option B:** This option is incorrect because the vertebral bodies are formed from the somites, which are block-like structures that form from the mesoderm and are located on either side of the notochord.
**Option C:** This option is incorrect because the spinal cord is formed from the neural tube, which is a separate structure that forms from the ectoderm and not from the notochord.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the intervertebral discs, particularly the nucleus pulposus, are highly susceptible to degeneration and injury, which can lead to conditions such as herniated discs and spinal stenosis.

**Correct Answer: C. Spinal Cord**