Given a nominal interest rate of 8 percent, in which of the following cases would you earn the highest after-tax interest rate? a. Inflation is 5 percent; the tax rate is 40 percent. b. Inflation is 4 percent; the tax rate is 30 percent. c. Inflation is 3 percent; the tax rate is 45 percent. d. Inflation is 2 percent; the tax rate is 50 percent