Why doesn't the united states export crude oil to other nations?

a. united states does not produce enough petroleum to meet the nation's energy needs, so the export of crude oil has been banned

b. oil-rich nations refuse to enter into trade agreements that would allow them to import crude oil from the united states.

c. the tariffs imposed on the export of crude oil by the federal government are too high for most american petroleum companies.

d. the cost of crude oil imported from the united states to nations around the world is too high for most countries to pay.