OPT:
[A]. stainless steel;
[B]. energy;
[C]. gold;
[D]. fibers;
[E]. LEDs;
[F]. tube;
[G]. wood;
[H]. rubber;

Fact 1: Wiring requires an electrical conductor. Fact 2: Most electrical conductors, such as wires, are made of copper or gold. Given the two facts above, wiring requires a material such as copper or what?
Answer:
[C].