Answer:
D. Medium of exchange
Explanation:
A medium of exchange is any physical object used as a measure of value to facilitate the transfer of goods and services between sellers and buyers. A medium of exchange acts as a go-between in transactions. In modern trade, money is the most widely accepted medium of exchange.
Today, goods and services are given a monetary value. Trade becomes relatively easy as buyers and sellers know how much money is needed to complete a transaction.
