B is the answer to this question. This was first used in Maastricht. For those who are not too aware, Maastricht can be found in the Netherlands. There was a treaty that was signed in the year 1992 in order to allow European Integration.

The European Union is considered to be important because this allows the various countries that are found in Europe to become more united with each other. At the same time, they can all work together in order to become more stable and secure.

This can also make it easier for people who are from various countries in Europe to travel to other spots in Europe easier. There are many advantages that are available to those who will become a part of this union.