The stated goal of the Organization of Petroleum Exporting Countries is to A
stabilize the market for oil.
B
remove barriers to trade in oil.
С
invest in new oil technologies.
D
standardize tariffs on crude oil

A.   stabilize the market for oil.

Explanation:

OPEC was an organization that was founded by the world's largest oil producers in order to control the price of oil in the market.

Before this organization exist, these large oil producers have to compete with one another in order to sell their oil in the market. As a result, they have to constantly lower the price of oil in order to increase the sales of their product. They soon realized that joining forces within one organization will be more beneficial for them rather than being competitors. Members of OPEC will create a standardized  oil price that must be followed by all members (none of them can sell their oil outside this standardized price). This helped  stabilize the market for oil.

c it has to be i googled it