What is the relationship between 'Petrobras' and 'gas' in the context of the input sentence.
Options: chief executive officer, product/material produced, distributed by, distribution format

But now, after about $250 billion of investment and the discovery of some of the world's largest offshore oil and gas resources, Petrobras is producing 2.8 million boepd, 20 percent less than its estimate for 2012 output.
product/material produced