How does the nervous system control all the systems in the body?

A. It transports signals/messages to and from the brain to make a certain body system responds.

B. It is only the nerve cell that controls all the body systems because it receives the signals from the environment.

C. It transports the signals received by the nerve cells to make a certain body system responds to the environment.

D. The spinal cord is connected to all the systems in the body as it is the passageway of the signals from the environment.​