Starting 1/1/14 and continuing each January 1 for four additional years, Case Corporation will deposit $10,000 in an account that will initially earn interest at a rate of 10%, credited each year on December 31. After the last deposit is made on 1/1/18, the account will earn 5% interest. What will be the approximate amount of the investment fund on December 31, 2020? Select one: o a. $67,309 O b. $70,674 oc. $74,040 O d. $77,741 O e. $73,871