The Finding That the Nerve Impulse Travelling Through the Body

The finding that the nerve impulse travelling through the body is slower than electricity travelling through a wire implied to researchers that

A) the nerve impulse is not electrical in its nature.
B) nerve impulses are more complex than simple electrical current.
C) the structures within the body impede the speed with which electrical current travels through the nervous system.
D) the brain and nervous system could be studied safely by stimulating them with weak electrical current.
E) electrical stimulation of the body could potentially damage the nervous system.