Deadweight loss measures the
选项：

A:a. loss in a market to buyers and sellers that is not offset by an increase in government revenue.;
B:b. loss in revenue to the government when buyers choose to buy less of the product because of the tax.;
C:c. loss of equity in a market due to government intervention.;
D:d. loss of total revenue to business firms due to the price wedge caused by the tax.