The correct option is 2 and 3, as Poland and Germany are both member states of the European Union (EU), which is a political and economic union of European countries that fosters economic cooperation and includes various member benefits such as the single market and customs union. In contrast, Belarus is not an EU member and has often been viewed as an isolated regime, while Switzerland is outside the EU, opting for bilateral agreements instead of full membership, reflecting its preference for maintaining sovereignty over its laws and regulations. This understanding is crucial for comprehending the dynamics of European integration and regional geopolitics, topics often highlighted in UPSC Prelims GS Paper I.