Which of the following description about the action potential of excitable cells is correct?

A、Action potential is a rapid and irreversible potential change that occurs when cells are stimulated.;
B、In the depolarization phase of the action potential, the membrane potential changes from inside positive to inside negative.;
C、The action potential repolarization phase is related to the opening of the Na+ channel and has nothing to do with the K+ ion channel.;
D、The amplitude of the action potential does not change with the stimulation intensity and conduction distance.