The association of three or more states created for mutual benefit and the achievement of shared objectives is a) environmentalism b) nationalism c) regionalism d) supranationalism

The association of three or more states created for mutual benefit and the achievement of shared objectives is supranationalism.
in this type of multinational political union a large amount of power given to an authority which in theory is placed higher than the state.
In Europe the authority is the European Union.

What are the choices