Aactive transport by the NaK pump Bthe opening of voltagegat

A.active transport by the Na+-K+ pump

B.the opening of voltage-gated Na+ channels

C. the opening of voltage-gated K+ channels

D.the closing of leakage channels in the axon membrane

Membrane potential (mV) /) +30 -55 :- 70 Time (ms)

From D to E, membrane is in hyperpolarisation phase. By this phase, all NA+ channels are already closed, and K+ channels also close at this stage.

Thereafter, Na+/K+ pumps operate to bring their concentration to resting conditions.

Hence correct answer is

A)	Active transport by Na+/K+ pump.