The correct answer that would best complete the given statement above would be the third option: EU. Citizens of EU or European Union are citizens of all the nations in the alliance. EU citizens are citizens of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and the UK. Hope this answer helps.