The market for _____ is an example of an oligopoly

According to the U.S. Treasury,

A) creditors do not have to accept cash in payment of debts. B) U.S. dollars must be accepted as payment for any good or service sold in the United States. C) firms do not have to accept cash as payment for goods and services. D) the government will not accept cash in payment of taxes.

By definition, economics is the study of

A) how to make money in a market economy. B) the choices people make to attain their goals, given their scarce resources. C) how to make money in the stock market. D) supply and demand.