The answer is D: She believes that world wars are harmful to people.
The author considers both the fault lines and the electrified fence of Communism as <em>common enemy</em> that, besides being harmful, they also served as focus for hatred and distrust. But now with the<em> end of them</em>, she feels that <em>a concern seems to indicate a threat of the national identity being eliminated by the African, Mexican and Irish. </em>