An investor purchases one Municipal and one corporate bond that pay rates of return of 8 percent and 10 percent, respectively.If the investor is in the 20 percent tax bracket, his after tax rates of return on the municipal and corporate bonds would, respectively be:(1 point)

a.8% and 10%

b.8% and 8%

c.6.4% and 8%

d.6.4% and 10%