3) Two cars travel along a level highway. It is observed that the distance between the cars is increasing. Which one of the following statements concerning this situation is necessarily TRUE (true no matter what)? A. The velocity of each car is increasing. B. At least one of the cars has a non-zero acceleration. C. The leading car has the greater acceleration. D. The trailing car has the smaller acceleration. E. Both cars could be accelerating at the same rate.