What flows in electricity?
A. Electrons
B. Protons
C. Neutrons

A) Electrons that is the correct answer

If its history of, then b) because a) implies only present day (now)

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other