Ileana received a statement on her Certificate of Deposit showing that her investment had returned $ 2500 over its life. If the Certificate of Deposit pays a simple interest rate of 5 % and her initial investment was $ 10,000, how long had the money been invested?
Select one:
a. 5 years
b. 9 months
c. 2.6 months
d. 4.2 years