Which statement best describes plastic's ability to conduct electricity? a) they are good insulators because their atoms have a single loosely bound electron in the outer shell that can move freely between other atoms. b)they are good insulators because they have electrons that are tightly bound in their shells which makes them unable to move between other atoms. c)they are poor insulators because the electrons in the atom are tightly bound and unable to move between other atoms. d)they are poor insulators because the electrons are able to move freely between the different energy levels within the atom.