Which one of the following is the correct grouping of different materials according to their electrical conductivity?

• A. Electrical Insulators Electrical Conductors Plastic/wood Mercury, tungsten
• B. Electrical Insulators Electrical Conductors Carbon, steel Iron, paper
• C. Electrical Insulators Electrical Conductors Copper, gold Nickel, clay
• D. Electrical Insulators Electrical Conductors Iron, rubber Silver, plastic