What is the primary purpose of the european union?
a. to create a common currency
b. to allow more trades between countries
c. to encourage immigration from one country to another
d. to permit workers to seek employment in international areas

The second alternative is correct (B).

The European Union is an economic bloc aimed at integrating European economies to increase trade between countries and between the bloc and the rest of the world.

Alternatives A, C and D are consequences of the creation of the European Union. The citizens of the bloc have become "European" and therefore can transit and work in all countries of the area, with less bureaucracy. However, the goal behind this is precisely to improve production and business conditions. Likewise, the single currency was created to facilitate this process.

can you post options?

yup! you are correct it is b.