When economists say that money serves as a medium of exchange, they mean that it is:

• A. used to facilitate the buying and selling of goods and services
• B. a measure of the value of all goods and services produced in an economy
• C. a store of wealth for future use
• D. used to regulate the supply of goods in the market

Answer: (A)

Verified step by step guidance

1. Understand the concept of 'medium of exchange' in economics: it refers to one of the primary functions of money that facilitates transactions between buyers and sellers.
2. Recall that money as a medium of exchange eliminates the inefficiencies of barter systems, where goods and services must be directly exchanged.
3. Recognize that money being a medium of exchange means it is widely accepted in exchange for goods and services, making trade easier and more efficient.
4. Compare the other options: 'a measure of value' relates to money as a unit of account, 'a store of wealth' refers to money's function as a store of value, and 'used to regulate supply' is not a standard function of money.
5. Conclude that the correct interpretation of money as a medium of exchange is that it is used to facilitate the buying and selling of goods and services.