European Union was established in 1992 by signing the.

Treaty of Maastricht

The correct answer is Option (2) - Treaty of Maastricht

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). 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.