Why are currency exchange systems important for international trade? A. They make it more difficult for countries to impose tariffs on foreign goods.
B. They make it more difficult for smugglers to sell foreign goods. They make it easier for people who speak different languages to trade with each other.
C. They make it easier for people who speak different languages to trade with each other.
D. They make it easier for countries with different kinds of money to trade with each other.