With a sense of crisis mounting and the EU unable to respond, countries will be increasingly inclined to act unilaterally or even---in the case of Britain--leave the bloc altogether. The refugee crisis is already threatening cherished ideas about open borders. In the past couple of days, Germany has reimposed frontier controls with Austria---which, in turn, has imposed controls at its border with Hungary, which itself is working feverishly to complete a barbed-wire fence to protect its frontier with non-EU Serbia. Controls have been tightened on the French-Italian borders, while migrants camp miserably in Calais, hoping to cross to England. If the EU somehow gets a grip on the migrant crisis, these measures might be no more than temporary expedients. But if the pressure of would-be refugees heading for Europe remain intense, then temporary measures could harden into permanent controls. Questions marks over open borders will easily shade into wider issues about access to welfare systems and labor markets. That is because EU countries are realizing that—in a border-free single market—a unilateral change of asylum rules by Germany had implications for the immigration policies of all member states. Once migrants get citizenship in one EU country, they have the right to move to any other, to work there and to claim benefits. But if free movement of people and labor come into question, so does the EU`s single market—its central achievement. The refugee issue has for the moment, overshadowed the euro. But the problems of the single currency have not gone away. On the contrary, Greece's decision this summer to knuckle under and accept yet another austerity package has made the Eurozone look increasingly like a trap. Even Greece, which is profoundly unhappy with life in the Eurozone, cannot risk leaving for fear of provoking a financial and economic crisis. Creditor countries such as Germany and the Netherlands are not much happier, as they fear they are being dragged into a system of permanent fiscal transfers towards the nations of Europe. Meanwhile, efforts to make the euro work better, by pressing ahead with a banking union, are stuck in Brussels. This does not look like a sustainable situation and the risk of euro break-up will surely return. The refugee and euro crisis bear on whether Britain will vote to stay in the EU, when it holds a referendum in 2016 or 2017. Until recently, the opinion polls looked promising for the pro-EU camp. But the migrant crisis plays directly into the most potent issue deployed by those campaigning for Britain to leave-which is that membership of the EU means that the UK cannot control immigration. More broadly, the British are less likely to stay inside an organization that seems to be failing. If they vote to leave, the sense of crisis within the EU would then mount--raising the possibility of further defections. A partial unravelling and marginalization of the EU still looks more likely than a full-scale collapse. But even if an organization called the European Union continues to exist--- running buildings and paying salaries---it risks becoming increasingly irrelevant. We can infer from the passage that___.
A. The idea of open borders will no longer exist. B. EU’s central achievement is its single market. C. Members in EU seem incapable of coming up with effective responses to their problems. D. To avoid sorry fates, members of EU must cooperate and take collective actions to deal with the common problems.