Which of the following is the poor conductor of electricity?

Conductors: ​Atoms of conducting materials have free electrons in them. ​When a charged body is brought in contact with a conductor, the charges are transferred to the conductor until the force of repulsion between electrons in areas of excess electrons is decreased to a minimum value. Good conductors are materials that allow charges to flow through them. ·         Carbon  is non-metal and there are no free electrons to conduct. Hence, it is a  poor conductor of electricity.