What is the relationship between 'Codelco' and 'copper' in the context of the input sentence.
Options: member of, publisher, position held, product/material produced

The layoffs come as the company is implementing a roughly 50 per cent drop in mining, stacking and crushing rates at the mine, in which Freeport owns a 51 per cent stake and Chilean state-owned copper giant Codelco has the remaining 49 per cent interest.
product/material produced