45 POINTS!!!!!!!!!!
Why is an international system for currency exchange needed?

A. Countries use the same currency, so a system is needed to prevent trade barriers.
B. Countries use different currencies, so a system is needed to know the value of currency for trade.
C. Countries use different currencies, so a system is needed to establish trade barriers.
D.
Countries use the same currency, so a system is needed to pay for imports and exports.