Utilize the input text as a context reference, choose the right relationship between Oz Minerals and copper from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

He also signalled that Oz Minerals wouldn't restrict itself to copper and gold assets if it found value in other commodities.

Answer: product_or_material_produced