Analyze the relationship between 'gold mine' and 'gold' within the context of the input sentence.
Options: member of, legal form, product/material produced, location of formation

The mine began production in 2013, and is the only primary gold mine in the world with annual production of more than one million ounces of gold (100% basis), at all-in sustaining costs below $700 per ounce.
product/material produced