Which of the following is a true statement about the biological regulation of thirst in the brain?

• A. the brain has a “drink system,” but does not have a “stop drinking system.”
• B. the brain has a “stop drinking system,” but does not have a “drink system.”
• C. the brain has both a “drink system” and a “stop drinking system,” and these control centers use the same neurotransmitters as the control centers for hunger.
• D. the brain has both a “drink system” and a “stop drinking system,” but these control centers use different neurotransmitters from the control centers for hunger.