* Sound: The speed of sound in air is about 343 meters per second (767 mph).

* Nerve Message: Nerve impulses travel at a range of speeds, but even the fastest ones are much slower than sound, typically around 100 meters per second (224 mph).

* Electricity: The speed of electricity, which is the flow of electrons, is incredibly fast. It travels at close to the speed of light (see below).

* Light: The speed of light in a vacuum is the fastest speed possible in the universe, approximately 299,792,458 meters per second (670,616,629 mph).

Therefore, the fastest speed out of the options you listed is the speed of light.