The correct answer is C. Insulators obstruct the flow of electrons whereas conductors allow electrons to flow freely.
Step-by-step explanation:
Electricity refers to the flow or existence of an electrical charge that is connected to electrons. In this context, conductor materials refer to those materials that allow electricity to flow freely, this includes materials such as steel or copper. On the other hand, insulators are materials that stop or obstruct the flow of electrons and therefore the flow of electricity which includes materials such as wood or rubber. According to this, the statement that compares insulators and conductors is "Insulators obstruct the flow of electrons whereas conductors allow electrons to flow freely".