Question

practice it
small knob at the end of the axon that releases neurotransmitters
neurotransmitter
dendrite
cell body
terminal button
axon

Explanation:

Terminal buttons are small knobs at axon - ends that release neurotransmitters. Neurotransmitters are chemical messengers, dendrites receive signals, the cell body contains the nucleus, and the axon transmits electrical impulses.

Answer:

D. terminal button