When the Na+/ K+ Pump Moves Its Bound Molecules of Na

When the Na+/ K+ pump moves its bound molecules of Na+ to the outside of the membrane, it

A) immediately returns to the inside of the cell, ready to transport more Na+ back outside.
B) pumps more K+ back into the cell than the amount of Na+ that just came out.
C) binds to ATP to release the energy required to power the return trip.
D) cannot return to the inside empty- handed, so it must bind two K+ first.
E) releases the bound ATP to return to its normal confirmation.