The currency that the European Union introduced to monitor currency exchange rate was the Euro.
The Euro is a currency that is used by almost all members of the European Union.
The purpose for it being introduced was to facilitate trade and to have a common monetary policy. It also allowed for the easier controlling, and monitoring of, exchange rates.
In conclusion, this is the Euro.
Find out more on the Euro at https://brainly.com/question/1563504.