Which of the following chemical signaling molecules functions primarily as a neurotransmitter?
Answer
Acetylcholine
Explanation
The slides include a section labeled **Acetyl choline** under the neurotransmitter material. The other options appear elsewhere in hormone classification or are not identified as the named neurotransmitter example in this section.\n\n**Key takeaway:** Acetylcholine is the neurotransmitter example explicitly named in the supplied material.\n\n**Glossary:** **Acetylcholine**: A chemical named in the slides as a neurotransmitter; **neurotransmitter**: A chemical signal transmitted across a synapse.