<prompt> The repolarization phase of an action potential is due toIncreasing sodium permability and increasing potassium permeabilityIncreasing sodium permeability and decreasing potassium permeabilityDecreasing sodium permeability and an immediate increasing potassium permeabilityDecreasing sodium permeability and a delayed increase potassium permeability  <response>: There is a decrease in sodium permeability inactivation of the sodium channels and a delayed increased in potassium permeability during the repolarization phase of the action potential. The pump plays no direct role in the action potential. 