In october of 1973, opec- the organization of petroleum exporting countries- joined together and refused to allow the united states to purchase oil from its member countries. as a result, by spring of 1974 oil prices had roughly tripled in the united states. what international trade situation is being described here? a) a quota b) a surplus c) an embargo d) an opportunity cost in october of 1973, opec- the organization of petroleum exporting countries- joined together and refused to allow the united states to purchase oil from its member countries. as a result, by spring of 1974 oil prices had roughly tripled in the united states. what international trade situation is being described here? a) a quota b) a surplus c) an embargo d) an opportunity cost