The Distance Traveled by a Car in the X-Direction Is

Multiple Choice

The distance traveled by a car in the x-direction is shown.When the car changes speed for t = 10 s to 15 s,it does so uniformly.Use the graph below to answer the question.
-The speed of the car at 5 s is

A) 5 m/s
B) 7.5 m/s
C) 10 m/s
D) 12.5 m/s
E) 15 m/s