Answer:
The change in momentum of the system due to the collision is 0 kg-m/s.
Step-by-step explanation:
It is given that,
Initial velocity of car 1,
(north)
Initial velocity of car 2,
(south)
Mass of each cars,

It may be the case of elastic collision, such that they will exchange their velocities. So, the final speed of both the cars will be :
Final velocity of car 1,
(south)
Final velocity of car 2,
(north)
The change in momentum of the system due to the collision is equal to the final momentum minus initial momentum. So, it is equal to 0 kg-m/s. Hence, the correct option is (d) " 0 kg-m/s".