The Significance of Galvani's Experiment Involving Stimulation of an Isolated

The significance of Galvani's experiment involving stimulation of an isolated frog muscle is that it proved that

A) fluid flow along nerves causes muscles to contract.
B) the muscles are activated by electrical nerve signals.
C) reflexes can be explained using a hydraulic model.
D) a reflex is a process controlled by the mind.
E) the mind controls the movements of the body.