Respuesta :
Many countries of Western Europe are part of D.) The European Union . The league of nations was created to prevent wars after WW1. SEATO stands for Southeast Asia Treaty Organization and NATO stands for North Atlantic Treaty Organization via process of elimination i believe D.0 is your correct answer i hope this helps you.
Answer: European Union
Explanation: Much of Western Europe is part of the European Union which is trying to make the continent into something like a United States of Europe. The countries do not tax goods moving between them. As of the year 2002, they replaced their national currencies with the same money, called the euro, in the form of euro notes and coins.