Your Aunt Ruth has $520,000 invested at 6.5%, and she plans to retire. She wants to withdraw $40,000 at the beginning of each year, starting immediately. How many years will it take to exhaust her funds, i.e., run the account down to zero?

a. 24.79

b. 29.55

c. 25.04

d. 23.29

e. 25.79