Which statement correctly compares an elastic collision with an inelastic collision?

1. Momentum conservation follows from the equal and opposite forces the two bodies exert on each other. 2. That argument does not care what happens to the shape of the objects, so it holds for every collision. 3. Kinetic energy is different, because bending and crushing take energy away from the motion. 4. An elastic collision keeps the total kinetic energy the same, an inelastic one does not. 5. So kinetic energy is conserved only in the elastic case, which rules out the second option. _Source: Siyavula Physical Sciences Grade 12 (Everything Science, CC BY 4.0), Chapter 2: Momentum and impulse_