9. The rate of change of the population of a town in Pennsylvania at any time t is proportional to the population at that time. Four years ago, the population was 25,000. Now, the population is 36,000. Calculate what the population will be six years from now.
A. 43,200 B. 52,500 C. 62,208
D. 77,760 E. 89,580
Population is found using an exponential function.