Utilize the input text as a context reference, choose the right relationship between Codelco 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.

Both Codelco and the contractor companies say paying more in benefits is unrealistic at a time when the copper price is at multi-year lows.

Answer: product_or_material_produced