What is the relationship between Codelco and copper in the context of the input sentence. Choose an answer from: 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.

SANTIAGO, Sept 28 The world's No.1 copper producer Codelco said on Monday that it was reducing the number of executives on its payroll by 15.6 percent, as the Chilean state-owned miner cuts costs in the face of tumbling prices for the industrial metal.

Answer: product_or_material_produced