If the ricardian equivalence theorem is not relevant, then an income-tax-rate cut a. will result in a multiple times higher increase in equilibrium real gdp in the long run; however, a tax-rate reduction will increase the automatic-stabilizer properties of the tax system, so equilibrium real gdp would be more stable. b. will result in a multiple times higher decrease in equilibrium real gdp in the long run, however; a tax-rate reduction will reduce the automatic-stabilizer properties of the tax system, so equilibrium real gdp would be more stable. c. will result in a multiple times higher increase in equilibrium real gdp in the short run; however, a tax-rate reduction will reduce the automatic-stabilizer properties of the tax system, so equilibrium real gdp would be less stable. d. will result in a multiple times higher decrease in equilibrium real gdp in the short run; however, a tax-rate reduction will increase the automatic-stabilizer properties of the tax system, so equilibrium real gdp would be less stable.