Which of the following best explains the difference between commodity money and fiat money?
A. Commodity money is usually authorized by the central bank, whereas fiat money has to be exchanged for gold by the central bank.
B. Commodity money has no value except as money, whereas fiat money has value independent of its use as money.
C. Fiat money has no value except as money, whereas commodity money has value independent of its use as money.
D. All money is commodity money, as it has to be exchanged for gold by the central bank.