What Is the Source of the Electrical Potentials Recorded from the Scalp

Multiple Choice

What is the source of the electrical potentials recorded from the scalp of a human subject?

A) the natural current found in skin
B) the signals generated by the contraction of muscle fibers that lie under the scalp
C) the summated activity of nerve cell action potentials and postsynaptic potentials
D) the signals generated by the activity of the sweat glands
E) the movements of our eyes