$\begin{array}{1 1} \text{a. In A, cars 1 and 2 will come closer and in B, cars 3 and 4 will come closer} \\ \text{
b. In A, cars 1 and 2 will move away from each other and in B, cars 3 and 4 will
move away.} \\ \text{
c. In A, cars 1 and 2 will move away and in B, cars 3 and 4 will come closer} \\ \text{
d. In A, cars 1 and 2 will come closer and in B, cars 3 and 4 will move away from
each other. } \end{array}$