Final answer:
The material that allows electricity to flow through it is known as a conductor. Conductors have free electrons or ions that facilitate the movement of electric charge, whereas insulators restrict this movement. Superconductors can conduct electricity with zero energy loss at very low temperatures.
Step-by-step explanation:
A conductor is any material which allows electricity to flow through it. The correct answer to the question is option a. Conductor. Materials like metals and salty water are examples of conductors because they have free electrons or free ions that allow charges to move relatively freely through them. This contrast with insulators, such as plastic or glass, where electrons are tightly bound to atoms and do not allow easy movement of charge through the material. Furthermore, the existence of superconductors demonstrates materials that can conduct electricity without any loss of energy, which is a property they exhibit at very low temperatures. On the other hand, resistance is a property of material that impedes the flow of electric current, and good conductors like copper, gold, or silver, have very low resistance.