Answer: A. Nerve cells in the skin feed the information to the hypothalamus.
Step-by-step explanation:
The hypothalamus is a part of the brain which controls the body temperature. The nerve cells present on the skin sends the signals to the hypothalamus when the body experience warm external temperature, which sends the signals to the sweat glands so that it's secretion makes the body cool. When the body feels cold then the hypothalamus sends the signal to the muscles to produce shivering to keep the body warm.