Which of the Following Statements About Action Potentials Is FALSE

Which of the following statements about action potentials is FALSE?

A) Action potentials operate on an all-or-none principle whether a cell either "fires" or it does not.
B) Action potentials are regenerative and, once started, they continue the length of the axon.
C) Action potentials operate differently than graded potentials.
D) Action potentials are bidirectional and can flow either up or down an axon.