Any Item Can Function as a Medium of Exchange

Any item can function as a medium of exchange

A) as long as the item is easily available
B) as long as the item is generally accepted in trade for most goods and services and for repayment of debt
C) but only if it is backed by some precious metal
D) but only if the item has been issued by the Federal Reserve for use as a medium of exchange
E) but only if the Treasury Department has designated that item as a medium of exchange