If the tip of the axon is on the left, and the receiving neuron is on the right, which direction is a neurotransmitter molecule that was just released most likely to move? A. Left
B. Right
C. Either up or down
D. Either left or right
E. All directions equally likely

The correct answer is - option B. right.

Explanation:

There is always unidirectional movement of neurotransmitters found.  Neurotransmitter molecules move to the dendrites of the receiving neuron ( located at the right) from the axon tip or axon terminals ( found at left).

Neurotransmitter molecules are stored in vesicles present in the axon terminal or tip. When the action potential reaches the terminal, the axon tip opens due to voltage-sensitive calcium channels present in them, releases the neurotransmitter molecules from the axon tip into the synapse.

Thus, the correct answer is - option B. right.