When the neuron becomes depolarized, it means
a. the inside is becoming positive
b. the inside is becoming negative
c. the neuron is degenerating
d. the inside is neutral

The inside is becoming positive.

Explanation:

The membrane potential may be defined as the difference in the electric potential between the outside and inside of the cell. This potential difference is important for the conduction of nerve impulse.

The depolarization of the cell occur due to the movement of sodium ions inside the cell. The depolarization of the cell changes the membrane potential from -70mV to +30mV. The inside of the cell become more positive than outside of the cell.

Thus, the correct answer is option (a).