What Distinguishes Fiat Money from Other Types of Money

What distinguishes fiat money from other types of money?

A) Fiat money serves as a medium of exchange while other types of money are not mediums of exchange.
B) Fiat money serves as a store of value while other types of money are not stores of value.
C) Fiat money is provided in standard units of account while other types of money are not provided in standard measures of value.
D) Fiat money has value because it is accepted by the public as money while other types of money may have monetary value based on the material of which the money is made.