This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Excitation and Action Potiential, Subject name: Physiology
Which one of the following neurotransmitters functions to increase cardiac output? 
Select and explain. 
A. GABA, B. Serotonin, C. Norepinephrine, D. Glutamate
C: Norepinephrine
Answer: C: Norepinephrine 
Explanation: Norepinephrine increases cardiac output Dopamine and GABA are CNS inhibitors. Glutamate is the most common excitatory neurotransmitter of the CNS. Serotonin functions as a pain inhibitor, in mood control and in sleep. Serotonin is a biogenic amine but not a peptide