What characterizes an insulator in terms of conduction?

An insulator is characterized by its ability to resist the flow of electric current. This characteristic is typically conveyed through its conductivity, which is very low compared to conductors. In the context of the correct answer, negligible conduction that increases with temperature accurately describes the behavior of most insulating materials.

As temperature rises, the thermal energy can excite some electrons in the insulator, increasing their energy levels and allowing a small number of them to jump into the conduction band. This results in a slight increase in conductivity, albeit still at a very low level compared to conductors. Thus, while the conduction is minimal at lower temperatures, it can become somewhat more significant as temperature increases; however, the overall conduction remains negligible.

The other options misrepresent the properties of insulators. High conduction at ambient temperature would indicate the material behaves more like a conductor, while the notion of negation of any conduction possibility does not accurately reflect the behavior of insulators, as they can still conduct to some extent under certain conditions. Complete conduction at elevated temperatures suggests the material behaves like a semiconductor or a conductor, which is not a characteristic of insulators.