Identify two new members of European Union who joined it in May 2004.

Estonia and Poland

The correct answer is option (3) - Estonia and Poland

Estonia and Poland joined European Union in May 2004.

The Treaty of Maastricht, formally known as the Treaty on European Union, was signed in 1992 and laid the foundations for the European Union (EU) as we know it today. It established the EU as a political and economic union, creating the framework for a common foreign and security policy, as well as a single currency, the Euro.