Which structure helps to shield copper wires from interference?

The correct structure that helps to shield copper wires from interference is foil shielding. This type of shielding is designed to block electromagnetic interference (EMI) and radio frequency interference (RFI) that can affect the performance of data transmission over copper wires. Foil shielding typically consists of a thin layer of conductive material that surrounds the wires. It works by creating a barrier that prevents external signals from interfering with the signals being transmitted within the wires, resulting in clearer signals and improved performance.

On the other hand, while plastic insulators do cover copper wires, their primary function is to provide electrical insulation to prevent short circuits and protect against electrical shock, rather than to shield against interference. Metal connectors serve the purpose of connecting wires but do not provide shielding. Fiber optic sheaths are used in fiber optic cabling to protect the delicate fiber strands but are unrelated to copper wiring.