Take context from the input text and decide on the accurate relationship between 'Pebble Mine' and 'copper' from the options provided.
Options: chief executive officer, position held, legal form, product/material produced

Before going to Kotzebue, Obama went to Dillingham, home to one of the world's largest sockeye salmon fisheries, where residents are fighting the Pebble Mine copper and gold project that has been proposed by Northern Dynasty Minerals Ltd .
product/material produced