The correct answer is option 'A': Cartilage.

Cartilage is present between the adjacent bones of the vertebral column. It is a type of connective tissue that provides support and flexibility to the bones. Cartilage is a smooth, firm, and flexible tissue that covers the ends of bones, allowing them to move against each other without friction.

Explanation:

1. Structure of the vertebral column:
The vertebral column, also known as the spine or backbone, is a flexible column of bones that extends from the skull to the pelvis. It consists of a series of individual bones called vertebrae, which are stacked on top of one another. The vertebrae are separated by intervertebral discs and held together by ligaments.

2. Function of intervertebral discs:
The intervertebral discs are cartilaginous structures located between each pair of adjacent vertebrae. They act as shock absorbers, cushioning the vertebrae and allowing for movement and flexibility of the spine. The discs also help to maintain the spacing between the vertebrae, which is important for the proper functioning of the spinal nerves.

3. Structure of cartilage:
Cartilage is a specialized type of connective tissue that is characterized by its firm yet flexible nature. It is composed of cells called chondrocytes embedded in a matrix of collagen fibers and proteoglycans. The collagen fibers provide strength and support, while the proteoglycans attract and hold water, giving cartilage its ability to resist compression.

4. Role of cartilage in the vertebral column:
Cartilage is present between the adjacent bones of the vertebral column, including the vertebrae and the intervertebral discs. It helps to reduce friction between the bones, allowing for smooth movement and flexibility of the spine. Cartilage also helps to absorb shock and distribute pressure evenly across the vertebral column, protecting the spinal cord and nerves.

In conclusion, cartilage is present between the adjacent bones of the vertebral column. It provides support, flexibility, and shock absorption, allowing for smooth movement and protection of the spinal cord.