When the brain receives the message that the environment around the body is very cold, the temperature signal begins in neurons of the

Temperature receptors detect the cold and send signals toward the brain through sensory neurons. These neurons belong to the sensory nervous system; the central nervous system receives and processes the message, while the autonomic nervous system may help trigger responses such as shivering. So the correct choice is the sensory nervous system.

AI-written and checked against the verified answer.