What of the following is a form of fiat money that is commonly used today?

A common form of Fiat money used today is the paper currency issued by governments, such as the US dollar, the euro, or the yen. Unlike commodity money, which is backed by physical assets like gold or silver, fiat money has value primarily because a government maintains it and people have faith in its worth. This trust allows it to be widely accepted for transactions and as a store of value.