Once the body has begun shivering, what happens to make it stop shivering? a) when body temperature returns to normal, the respiratory system sends a message to the skeletal system to stop shivering. b) when body temperature returns to normal, the nervous system sends a message to the muscular system to stop shivering. c) when body temperature is below normal, the nervous system sends a message to the skeletal system to stop shivering. d) when body temperature is below normal, the respiratory system sends a message to the muscular system to stop shivering.