Utilize the input text as a context reference, choose the right relationship between 'Chuquicamata' and 'copper' from the options.
Options: director/manager, developer, product/material produced, distribution format

The Chuquicamata mine, located 1,650 kilometers (1,000 miles) north of Santiago, produces around 339,000 tonnes of copper per year, making it one of the company's most productive sites.
product/material produced