If the velocity of a car traveling in a straight line at time v(t) then the difference in its odometer readings between time t=a and t=b is
A. integral a to b of the absolute value of v(t)dt
B. integral a to b of v(t)dt
C. the net displacement of the car's position from t =a to t =b
D. the change in the car's position from t = a to t = b
E. none of these