Nelson has the choice between investing in a city of Fruithurst bond at 4.2 percent or a J.B. Ribs, Incorporated bond at 5.4 percent. Assuming that both bonds have the same nontax characteristics and that Nelson has a 40 percent marginal tax rate, in which bond should he invest? What interest rate offered by J.B. Ribs, Incorporated would make Nelson indifferent between investing in the two bonds?