Which of the following forms of economic integration is a member nation free to impose duty against non-members

A free trade area is a form of economic integration where member nations agree to eliminate tariffs and trade barriers on goods and services traded among themselves. However, each member nation is still free to impose duties against non-member nations. In other words, members have a free trade agreement with each other, but they can still have their own trade policies towards non-members. In contrast, a customs union is an advanced form of a free trade area where member nations not only eliminate tariffs among themselves, but they also agree to have a common external tariff towards non-member nations. This means that all goods entering the customs union must pay the same tariffs, regardless of which member nation they are entering. A common market is a further step towards integration, where not only goods, but also factors of production such as capital and labor can freely move among member nations. This allows for a more integrated and efficient market, but it also means that member nations have less control over their trade policies. An economic community is a broader form of integration, where member nations agree to coordinate and harmonize their economic policies in a wide range of areas, including trade, monetary policy, and fiscal policy. This is the most advanced form of integration, as it involves a high degree of cooperation and coordination among member nations.