The correct answer is A. The Great Schism or the East-West Schism represented the final separation between the Eastern Christian churches (whose leader was Michael Cerularius, the <u><em>patriarch of Constantinople</em></u>) and the Western one whose leader was Leo IX. There were excommunications that ended in 1965, when Pope <em>Paul VI</em> and <em>Athenagoras I</em> revoked the excommunications decrees.