Which statement is true about this function?
a. There is no way to compare the instantaneous rate of change at t = 9 and t = 3.
b. The instantaneous rate of change at t = 9 is larger than that at t = 3.
c. The instantaneous rate of change at t = 9 is smaller than that at t = 3.
d. The instantaneous rate of change at t = 9 is the same as that at t = 3.