Option 1 -> Fiduciary money refers to money backed by trust in the issuer but is not the standard term for modern currency.
Option 2 -> Intrinsic value money has inherent worth (like gold/silver coins), which modern currency notes do not possess.
Option 3 -> Currency notes and coins ARE legal tender, not non-legal tender money.
Option 4 -> Fiat money is government-issued currency not backed by physical commodities, deriving value from government decree.
Hence, Option 4: Fiat money -> Currency notes and coins are termed as fiat money because they have no intrinsic value and are not backed by physical commodities like gold or silver. Their value is derived from government regulation and decree, which declares them as legal tender for transactions. The term "fiat" comes from Latin meaning "let it be done," indicating that money has value by government order rather than by the material it's made from-> correct