Juanita earns $56,000 a year before-tax, spends $31,500 per year on consumption, and saves the rest at the end of the year. She also has $14,400 in her savings account. She wants to retire in 25 years with a million dollars. Her average tax rate is 25%, and her marginal tax rate is 35%. What before-tax rate of return does she need to make on her investments in order to achieve her goal?

a. 8.99%

b. 13.71%

c. 5.13%

d. 6.49%

e. None of the above.