Final answer:
The sacrum is located below the lumbar vertebrae and is part of the vertebral column. It is formed by the fusion of five sacral vertebrae and completes the spine at its lower end.
Step-by-step explanation:
The sacrum is located below the lumbar vertebrae. It is part of the vertebral column, which is divided into several regions: the cervical, thoracic, lumbar, sacral, and coccygeal. The sacrum is formed by the fusion of five sacral vertebrae and is located near the inferior end of the adult vertebral column. It is also a part of the pelvis, and along with the coccyx, completes the vertebral column at its lower end.
While the thoracic vertebrae are part of the thoracic region, supporting the rib cage and including 12 vertebrae numbered as T1-T12, the sacrum is well below this section, just after the five lumbar vertebrae designated L1-L5. The correct answer to the question about the location of the sacrum is B) Below the lumbar vertebrae.