According to the all-or-none law:

Question

a. all axons in an area will fight at a given signal.

b. an axon moves from its resting state with various degrees of stimulation.

c. only sufficient electrical activity will cause the axon to fire.

d. there is a gradual buildup of electrical activity before an axon can fire.

I think it is either c or d because I know that once there is enough force to pull the trigger, a neuron fires.