Final answer:
The correct extinguisher for an electrical fire is the Class C extinguisher, which is safe and effective for electrical fires without conducting electricity.
Step-by-step explanation:
The best type of extinguisher to use on an electrical fire is a Class C extinguisher. Class A extinguishers are designed for ordinary combustibles like wood and paper, Class B for flammable liquids like gasoline or oil, and Class D for combustible metals. For electrical fires that involve electrical equipment, the non-conductive properties of Class C extinguishers make them the safest and most effective choice as they will not conduct electricity back to the user.