Which of the Following is Mismatched

Question

Which of the following is mismatched?  
A) Acetylcholine; muscle contraction
B) Endorphin; pain perception
C) Norepinephrine; fight-or-flight response
D) Serotonin; sexual function
E) GABA; major inhibitor in the brain

Accepted Answer

Serotonin is primarily associated with mood regulation, sleep, and appetite. While it can have an impact on sexual function, it is not its primary function. Therefore, choice D is mismatched.