Answer:
The correct answer would be - the potassium ions continue to move out of the axon.
Step-by-step explanation:
During transmission of the impulse when sodium channels are closed and potassium channels are open, the cell membrane of the axon cell becomes hyperpolarized due to the continuous movement of the potassium ion to outside the axon. During this refractory period, the impulse can not be fire or generated.
Thus, the correct answer would be - the potassium ions continue to move out of the axon.