The central nervous system is responsible for many functions, including

The central nervous system includes the brain and spinal cord. The brain helps regulate automatic functions such as the sleep cycle, breathing rate, and body temperature, so “regulating the sleep cycle, breathing rate, and body temperature” is the best choice. Detecting sensations involves sensory receptors and nerves in the peripheral nervous system, while digestion is mainly controlled by the digestive system.

AI-written and checked against the verified answer.