Starting 1/1/15 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 5%, credited each year on December 31. After the last deposit is made on 1/1/19, the account will earn 10% interest. What will be the approximate amount of the investment fund on December 31, 2020? Select one: 0 $66,860 b. $60,782 C. $67,012 d: $70,363 c. $73,546