Suppose we artificially start one action potential at the axon hillock and another half-way down the axon. What will happen to the one starting at the axon hillock?

    a.    It will cross over the one started half-way down the axon and continue in that direction.
    b.    Nothing, it is not possible to generate an action potential at the axon hillock.
    *c.    It will be canceled when it encounters the other traveling towards it.
    d.    It will travel normally to the presynaptic terminals.