Translation:Each country has to produce its currency.
This is a bit sticky I think, because in English there needs to be an antecedent for "its". Hence, it could be "The Euro will be used by all countries in the EU. Each country must produce its currency." Otherwise, the proper (but not literal) English translation would be: "Each country must produce its own currency."
We're near the end of our course, so it's a good time to start relying more on external resources. Online French-English dictionaries are free and extremely convenient.
If you look up monnaie the first translation is "currency". The second translation is "change".
Also, other definitions, phrases, and examples are offered.
So your question is answered without reliance on Duo's rather shaky hints.