The correct answer is D. Conductors.
Conductors are materials that allow electricity to flow through them easily. They have a large number of free electrons, which are electrons that are not bound to any particular atom. These free electrons can move freely through the material, carrying an electric current.
Insulators are materials that do not allow electricity to flow through them easily. They have very few free electrons, so there are not many electrons available to carry an electric current.
Semiconductors are materials that have properties between those of conductors and insulators. They can be made to conduct electricity by adding impurities, or dopants, to the material.
Inductors are devices that store energy in a magnetic field. They are made up of a coil of wire, which creates a magnetic field when current flows through it.
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