A Paper Monetary Standard

A paper monetary standard:

A) is the worst monetary standard an economy can have.
B) exists when an economy's money is not backed by something of tangible value, like gold.
C) can succeed only if there is a reserve of a commodity available to back the money supply if needed.
D) is one where money is backed by something of high intrinsic value, but the public cannot redeem its money for the item used as backing.