Which Statement Accurately Describes an Action Potential

Which statement accurately describes an action potential?

A) Its magnitude increases along the axon.
B) Its magnitude decreases along the axon.
C) All action potentials in a single neuron are of the same magnitude.
D) During an action potential, the membrane potential of a neuron remains constant.
E) An action potential permanently shifts a neuron's membrane potential away from its resting value.