Bumper cars at an amusement park are designed to safely collide with one another. Why does a bumper car stop moving when it strikes another car?

Its energy is transferred to the other car.
Its energy is transferred to the other car.

Its energy is transferred to its surroundings.
Its energy is transferred to its surroundings.

The other car pushes back on it, so it cannot move forward.
The other car pushes back on it, so it cannot move forward.

The other cars are tightly packed, so forward motion is not possible.

The other cars are tightly packed, so forward motion is not possible.