First, it is important to understand that average kinetic energy is directly proportional to temperature. This means that the substance at the largest temperature will also have the largest average kinetic energy. Therefore, from largest to least, the average kinetic energies would be: Z, X, W, then Y. When you look at the answer choices, the only choice that makes sense is that the particles in substance W have a lower average kinetic energy than the particles in substance X because substance W is at a lower temperature than substance X.
I hope this helps.
