In which year was the European Union formed?

The European Union was officially established by the Maastricht Treaty, which was signed in 1991 and entered into force on November 1, 1993. This treaty marked a significant step in European integration, setting the groundwork for the EU's development, its political structure, and its economic policies. The creation of the EU allowed for the establishment of a common market, a unified currency, and a collective approach to various social and political issues among member states. Therefore, the choice indicating 1993 as the formation year is correct as it signifies the official launch of the European Union as an institutional entity.