One way in which the European Union encourages trade among countries is through the use of

Answer: B

Explanation:

B. a common currency

The European Union negotiates different agreements through its wide network of trade relations. It engages with countries mostly through free trade agreements. Partnerships seek to create growth and jobs for Europeans by opening new markets. Transatlantic markets are one good examples. Other mechanisms fight child labour, promote small business, give finacial aid and so on.