Which characteristic of waves does the movement of the salt best demonstrate?

The movement of salt in water best demonstrates the characteristic of wave propagation, specifically the transfer of energy. As waves travel through the water, they cause the salt to move, illustrating how energy can be transmitted through a medium without the permanent displacement of the particles themselves. This phenomenon highlights the oscillatory nature of waves, where the medium (water) facilitates the movement of substances (salt) in response to the energy of the wave.