A – Commodity 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.

Extra Question:

The mackerel money des described in the Making the Connection would be best thought of as (Fiat? or Commodity?) money.