Chemo is for cancer not benign
There are 5 groups in the vertebral column. In order they are called
1) Cervical
2) Thoracic
3) Lumbar
4) Sacrum
5) Coccyx
The 4th group contain 5 bones and once you are in the adult phase,
roughly at about 26 years, the 5 bones fuses into one bone which shrink
the number of bones the vertebra column have but but does not lose in
size.
not a 100 % sure hope this helps
A. Is the answer , because it is a theory
