Final answer:
The large European trading bloc is known as the European Union (EU), which was established to closely integrate the economies of its member states and avoid conflict.
Step-by-step explanation:
The large trading bloc made up of countries in Europe that you are referring to is the European Union (EU). The EU started as a free trade association, evolved into a common market, and later became a full economic union. After World War II, European leaders sought to integrate their economies to prevent further devastating conflicts. As a result, they introduced a common currency, the euro, and worked towards eliminating barriers to the mobility of goods, labor, and capital across member nations. Over the years, the European Union has grown and now includes 27 member countries. Other trading blocs include NAFTA in North America and ASEAN in Southeast Asia, but the correct answer to your question is a) European Union.