Is good conductor of electricity Camphor saltwater iodine diamond?

Among the options listed, saltwater is a good conductor of electricity due to the presence of ions that can move freely and carry electric current. Camphor, iodine, and diamond are not good conductors; they are generally insulators or poor conductors. Camphor is a non-polar compound, iodine is a molecular solid, and diamond, while a good thermal conductor, does not conduct electricity well due to its lack of free electrons.