Consider the motion of an object given by the position vs. time graph shown. For what time(s) is the speed of the object greatest?
(A) At all times from t = 0.0 s→ t = 2.0 s
(B) At time t = 3.0 s
(C) At time t = 4.0 s
(D) At all times from t = 5.0 s → t = 7.0 s
(E) At time t = 8.5 s