During an action potential, which of the following changes significantly? Group of answer choices

a) The concentration gradients for Na + and K+.

b) The number of Na + and K + ions crossing the cell membrane.

c) The membrane potential. The activity of the Na+/K + ATPase.

The process is ocurring by steps, starting with depolarization.

1 - Na + permeability > K + permeability

2 - Vm (membrane potential) approaches ENa + (quilibrium potential for potassium)

3 - K + permeability > Na + permeability

4 - Vm (membrane potential) approaches EK + (quilibrium potential for potassium)