Macmillan Learning When you start working, you are offered two retirement options. When you retire, you will be given the balance of a retirement account. Retirement option A: The initial balance is zero. The growth rate of your retirement fund A, in dollars, is given by dA dt Retirement option B: The initial balance is $9200. The growth rate of your retirement fund B, in dollars, is given by dB dt = 20000 = 0.1 B In each case, time t is measured in years. Find a formula that gives balances A and B for each retirement fund after t years. (Express numbers in exact form. Use symbolic notation and fractions where needed. Give the equations in terms of the dependent variable A or B and the independent variable t.) balance A equation