C. -$78.16/year
Another average rate of change. Just calculate the function for x = 5 and x=10. Then divide the difference between those two values by the difference in x, which is 5. So
4500(0.98)^5 = 4067.64
4500(0.98)^10 = 3676.83
(3676.83 - 4067.64)/5 = -390.81/5 =
-78.16
And that value matches option "C".