When the voltage of a plasma membrane shifts from + 30mv towards 0 mv, we say the cell is

a. depolarizing.

b. repolarizing.

c. hyperpolarizing.

d. reaching the threshold?

When voltage of a plasma membrane shifts from + 30mV towards 0mV, we say cell is repolarizing. Repolarization results from the movement of positively charged K + ions out of the cell. This repolarization phase of an action potential results in hyperpolarization, attainment of a membrane potential that is more negative than the resting membrane potential.