Which of the following explains why international trade requires a system for exchanging currencies between nations?

Without the ability to exchange currencies, dictatorships would be overthrown.

Without the ability to trade currencies, all countries would be democracies

Without the ability to trade currencies, buyers and sellers could not properly pay each other

Without the ability to trade currencies, more countries would follow command systems than market systems.

Without the ability to trade currencies, buyers and sellers could not properly pay each other