Which statement best explains how national boundaries influence the identity of ethnic groups divided by a boundary? ethnic groups that occupy more than one country strive for unification in their own separate nation-state. obstacles to migration push the ethnic groups’ cultural elites to work harder to maintain shared traditions. the members of ethnic groups divided between two or more countries learn different primary languages. social and economic differences promote a different kind of cultural development on either side of the border. separate political identities result in the fragmentation of divided groups into two completely distinct ethnic groups.