Which of the following contains the brain and spinal cord?

The correct answer is the central nervous system, which is composed of the brain and spinal cord. This system is responsible for processing and integrating sensory information, coordinating responses, and enabling complex functioning such as reasoning, memory, and emotions.

The central nervous system serves as the control center for the body, facilitating communication between the brain and the rest of the body through the spinal cord. The peripheral nervous system, in contrast, consists of all the nerves outside the central nervous system and is responsible for transmitting signals to and from the body.

The autonomic nervous system is a subdivision of the peripheral nervous system that regulates involuntary bodily functions such as heartbeat and digestion, while the somatic nervous system controls voluntary movements and conveys sensory information to the central nervous system. These systems are integral to overall function but do not encompass the central nervous system's critical roles.