The correct answer is D. The commodity is backbone of the United States money supply.
Money is a medium of exchange, a unit of account, and a store of value. It is an asset that provides liquidity and facilitates transactions. The United States money supply is largely composed of fiat money, which is money that is not backed by any physical commodity. Fiat money is created by the government and is accepted as payment because of the government’s promise to redeem it for goods and services.
The commodity is not the backbone of the United States money supply. The United States money supply is based on fiat money, which is not backed by any physical commodity.