Which of the Following Is Responsible for the Falling (Repolarizing)phase

Multiple Choice

Which of the following is responsible for the falling (repolarizing) phase of the action potential?

A) Voltage-gated Na⁺ channels are opened
B) The Na⁺, K⁺ pump restores the ions to their original locations inside and outside of the cell
C) The permeability to Na⁺ increases greatly
D) ATPase destroys the energy supply that was maintaining the action potential at its peak
E) The permeability to K⁺ increases greatly while that to Na⁺ decreases