What is the best explanation of electric current in a wire?

Hello. This question is incomplete. The full question is:

"What is the best explanation of electric current in a wire? A. Electrons build up in the wire and create a charge. B. Protons are pushed along by electric forces. C.Atoms move because of heat. D. Electrons flow because of electrical attraction and repulsion. "

D. Electrons flow because of electrical attraction and repulsion.

Explanation:

Electrical and electronic devices found in homes need electrical energy for their operation. Such energy is obtained when they are plugged into some source of energy, such as a battery or an outlet. When this is done, something invisible happens. Free electrons, which are found in the conducting means of these devices, start to move in an orderly manner, transporting the electrical energy necessary for their operation. This orderly movement of electrons is known as electrical current. When electrical current is dissipated through a wire, electrons flow because of electrical attraction and repulsion.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-