A student is building an electric circuit. Which material should she choose for the wires, and why?

If i understand your question clearly, The best choice in most scenarios is  copper.

Why?

Its due to copper's high conductive properties, its abundance, its low price compared to its fellow metal conductors, its ductile property, thermal resistance and immunity to oxidation ( rusting ).

Though Silver surpasses copper in conductivity, copper is shown to be more notable than its fellow conductors.