The table below shows the distance d(t) in meters that an object travels in t seconds:


t (seconds): 1, 2, 3, 4
d(t)(meters): 15, 60, 135, 240

What is the average rate of change of d(t) between 2 seconds and 4 seconds, and what does it represent?

A. 50 m/s; it represents the average speed of the object between 2 seconds and 4 seconds
B. 90 m/s; it represents the average speed of the object between 2 seconds and 4 seconds
C. 90 m/s; it represents the average distance traveled by the object between 2 seconds and 4 seconds
D. 50 m/s; it represents the average distance traveled by the object between 2 seconds and 6 seconds