4.75 percent coupon bond issued by the State of Washington sells for $1,000. What coupon rate on a corporate bond selling at $1,000 par value would produce the same after tax return to the investor as the municipal bond if the investor is in the 28 percent marginal tax bracket? a. 5.8% b. 1.1% c. 9.7% d. 7.3% e. 6.6%