The distance, d(t), in feet, a bug has traveled is shown in the graph. A coordinate plane with a function d of t consisting of a line starting at 0 comma 1 rising to 1 comma 2, a horizontal line from 1 comma 2 to 2 comma 2, a line falling from 2 comma 2 to 3 comma 1, and a line falling from 3 comma 1 to 6 comma 0.

Estimate the rate of change in the distance of the bug at time t = 4 seconds.

Select one:
a. negative one third
b. the limit as t approaches 4 of the function d of t feet per second
c. d(4) ft/s
d. 0.7 ft/s