The idea behind the Laffer curve is that increases in tax rates do not increase tax revenues proportionately because they decrease the: A: demand for labor. B: supply of labor. C: productivity of labor.

According to quantity equation the price level would change less the proportionately with a rise in the money supply if there were also A: either a rise in output or a rise in velocity. B: either a rise in output or a fall in velocity. C: either a fall in output or a rise in velocity. D: either a fall in output or a fall in velocity.