The correct answer is in a BARTER economy, individual goods are traded for other goods.
Barter is the act of trading goods or services between two or more people. They do not use money, checks or credit cards. Bartering could be understood by the exchange of one product or service in return for another product or service from another person.
No so long ago, bartering was the essential mean for trading. Like in the Aztec Empire in Mesoamerica. Before the Spanish conquest, many tribes like the Aztecs in Mexico, and some other tribes of South America, used bartering as a mean to Exchange products and services. One party share one pound of meat and the other gave three pounds of wheat.
All these changed with the use of currency or monetary system.