Final answer:
Dendrites occupy the least amount of cell volume among the parts of a neuron, being thin extensions that branch off from the cell body.
Step-by-step explanation:
The student's question asks to match the part of the neuron that occupies the least amount of cell volume. Of the options given, dendrites, axon, and cell body, the correct answer is dendrites. This is because dendrites are the thin extensions branching off from the cell body and, compared to the cell body and the axon, they occupy the smallest volume within the neuron.