Final answer:
The thoracic spine contains the largest number of vertebrae in the vertebral column with twelve vertebrae, surpassing the cervical and lumbar regions.
Step-by-step explanation:
In the vertebral column, the largest number of vertebrae occur in the thoracic spine, which is option (d). There are twelve thoracic vertebrae (Th1-12), which exceed the number of vertebrae in other regions such as the seven in the cervical spine (C1-7) and the five in the lumbar spine (L1-5). The cervical region, specifically the axis (C2), serves as the rotational axis for turning the head, distinguishing it from the thoracic spine's functionality. The thoracic spine's primary role, along with the thoracic cage, is to protect the organs within the chest and serve as an attachment point for the ribs.