Action potential creates the "depolarization of a neural membrane".
Option (a);
Step-by-step explanation:
A neuron manages electrical impulses using action potential. This is done through the flow of positive ions across the neuronal membrane. Due to the neurons, there is a different concentration of charged atoms on both sides of the cell membrane.
This difference in concentration of charge atom creates membrane potential and it is said to be polarized in nature. With the opening of sodium channels, positive neurons will flow inside the neuron and this is depolarization of the cell.
Thus it results in the potassium cells that move outside the cell. Also, the sodium channels in the neuronal membrane get's opened due to the effect of depolarization, create an action potential which activates other sodium channels.