What is one way that the united states does not restrict voluntary trade? a the united states outlaws certain types of business transactions, because they can harm the general population. b the united states is part of the north american free trade agreement, making it easier for companies in mexico and canada to sell their goods in the united states. c the united states imposes tariffs (taxes) on some imported goods, making them very expensive to buy in the united states. d the united states has imposed sanctions on the russian federation, making it so banks based out of the united states cannot do business with russian companies.