Answer:
Energy
Energy because water can carry forms of energy. If a wave can carry energy, this statement could be true.
Only water is untrue because there's soundwaves and pulse waves, so this statement can't be true.
It can't be matter because not all waves are made up of forms of matter. So waves are not made of only matter.
Only particles can't be right because there are forms of waves that do not produce to release any particles.
In this case, that would leave energy left, eliminating the others.
Hope it helps, if it doesn't, I can make it right.
