Which of the following statements about action potentials in a given neuron is false? a. all action potentials for a given neuron are identical in magnitude. b. all action potentials for a given neuron are identical in duration. c. action potentials are propagated down the length of the axon. d. movement of ions during the action potential occurs mostly through the sodium pump. e. the frequency of action potentials, not their size, is the meaningful signal.