Question

abnormal levels of ________ may lead to alzheimer’s disease.
a. endorphins
b. serotonin
c. gaba (gamma-aminobutyric acid)
d. acetylcholine

please select the best answer from the choices provided

○ a
○ b
○ c
○ d

Explanation:

Alzheimer's disease is associated with a decrease in acetylcholine, a neurotransmitter involved in memory and cognitive functions. Endorphins are related to pain relief and mood, serotonin to mood and sleep, and GABA to inhibitory signaling in the brain, none of which are primarily linked to Alzheimer's in the same way as acetylcholine.

Answer:

D. acetylcholine