Refer to the input text as context and select the correct relationship between 'Rosneft' and 'Petroleum' from the available options.
Options: member of, product/material produced, publisher, parent organization

On the supply side, recent speculation that Russia might be willing to cooperate with the Organization of the Petroleum Exporting Countries (OPEC) to curb output in support of prices was given a blow on Monday after the chief executive of Russian oil major Rosneft ruled out a Russian cut.
product/material produced