A 7-year municipal bond yields 4.80%. Your marginal tax rate (including state and federal taxes) is 32.00%. What interest rate on a 7-year corporate bond of equal risk would provide you with the same after-tax return? (Round your final answer to two decimal places.)

a. 7.93%

b. 7.23%

c. 7.30%

d. 7.06%

e. 6.12%