Van Duke Corporation has a corporate tax rate equal to 33%. The company recently purchased preferred stock in another company. The preferred stock has an 8% before-tax yield. What is Van Duke's after-tax yield on the preferred stock? Assume a 70% dividend exclusion for tax on dividends. (Round your final answer to two decimal places.)

a. 8.94%

b. 7.28%

c. 7.21%

d. 6.27%

e. 7.42%