Which of the following is a subdivision of the central nervous system?

The central nervous system (CNS) is the part of the nervous system that consists of the brain and the spinal cord. The brain is the control center of the nervous system and is responsible for regulating most of the body's functions.

The spinal cord is a long, thin, tubular structure that extends from the brainstem down through the center of the back. It is responsible for transmitting signals between the brain and the rest of the body, as well as coordinating reflexes.

Hence, the correct option is the brain and spinal cord.