Utilize the input text as a context reference, choose the right relationship between 'Noble Group' and 'energy' from the options.
Options: director/manager, distributed by, headquarters location, product/material produced

LONDON—Commodities trading giant Noble Group Ltd is winding down its exposure to some metals and focusing on what it says is a profitable energy business as it addresses the global resources rout that has made the Singapore-listed firm a big focus for investors looking for casualties amid the carnage.
product/material produced