The graph represents the acceleration of two cars, Accel 1 and Accel 2, during a road trip. Which statement BEST describes the differences between the two cars' acceleration during the trip?
A) Accel 1 accelerates throughout the entire trip; Accel 2 does not accelerate during the trip.
B) Accel 1 rapidly accelerates and then stops; Accel 2 maintains a constant velocity during the trip.
C) Accel 1 has a constant rate of acceleration; Accel 2 accelerates at different rates during the trip.
D) Accel 1 accelerates for the first two-thirds of the trip; Accel 2 has a constant rate of acceleration.
