In which situation does the reactive force between two colliding objects cause a physical change?

Question

The swing hitting another swing causing the second swing to move
To bumper cars and amusement park colliding causing both cars to change directions
The best baseball player swinging a bat and hitting a baseball causing the bat to shatter
The exhaust from rocket thrusting the rocket away from the ground

Answer 1

The best baseball player swinging a bat and hitting a baseball causing the bat to shatter