Study the following picture and answer the question.

Which currency is used as legal tender among the member countries of this international organisation?

Euro

The correct answer is option (1) - Euro

Euro is the currency used as legal tender among the member countries of European Union.  Members of the European Union who have adopted the Euro currency are called the Eurozone. However, one can't ignore that there is also a deep-seated ‘Euro-skepticism’ in some parts of Europe about the EU’s integrationist agenda. Thus, for example, Britain’s former prime minister, Margaret Thatcher, kept the UK out of the European Market. Denmark and Sweden have resisted the Maastricht Treaty and the adoption of the euro, the common European currency.