Answer: Option (B) is the correct answer.
Explanation:
An insulator is a substance which causes high resistance to the flow of free electrons. This means that an insulator does not allow the flow of electrons or electric charges through it.
For example, rubber, plastics, and styrofoam etc are all insulators.
On the other hand, a conductor is defined as a substance through which an electric current is able to flow freely without causing any resistance due to the availability of free electrons.
For example, silver, copper, gold etc are all good conductors of electricity.
Thus, we can conclude that an insulator stop the flow of an electric current because insulators do not allow electrons to move easily through them.
