If a Few Oil-Producing Countries in the Middle East Decide

If a few oil-producing countries in the Middle East decide to jointly limit the production of oil,

A) they are forming a cartel.
B) they would like the price of oil to be the same as if the market were perfectly competitive.
C) game theory does not apply to their actions because they are nations, not firms.
D) they will try to operate as a large, monopolistically competitive firm.
E) they will agree to lower the price of oil in order to increase their profits.