Consider the following statements about the European Union: 1. I. The European Union was known earlier as the European Community. 2. II. The Single European Act (1986) and the Maastricht Treaty were milestones in its formation. 3. III. Citizens of European Union countries enjoy dual citizenship. 4. IV. Switzerland is a member of the European Union. Which of the above statements are correct?

1. Statement I: The European Union (EU) was indeed known earlier as the European Economic Community (EEC) or simply the European Community (EC). This statement is correct. 2. Statement II: The Single European Act (1986) and the Maastricht Treaty (1992, effective 1993) were crucial milestones. The Single European Act aimed to create a single market, and the Maastricht Treaty formally established the European Union. This statement is correct. 3. Statement III: Citizenship of the EU is supplementary to national citizenship. Citizens of member states are automatically EU citizens, enjoying certain rights like free movement, but they primarily hold citizenship of their own country. The concept of dual citizenship in this context (national + EU) is essentially correct in terms of rights and identity conferred by the EU. This statement is generally considered correct in the context intended. 4. Statement IV: Switzerland is not a member of the European Union, though it has close ties through various agreements. This statement is incorrect. 5. Based on the analysis, statements I, II, and III are correct.