The correct answer is B) have a value expressed in both fiat money and commodity money.
Money serves as a unit of account when goods have a value expressed in both fiat money and commodity money.
There are three basic functions of money as we know it. The first is the basic one. Money serves as a medium of exchange for goods and services. Money stores value and wealth. It also is used as a unit of account. After many years of barter, money changed the way trade was done. It facilitated commerce and the interchange of products. With money as a unit of account, we can compare the costs of producing goods.
