The best response to describe a similarity and a difference between the particles in liquid water at 100ºC and the particles in steam at 100ºC is:
The particles have the same amount of energy, but steam particles are spaced farther apart.
At 100ºC, both liquid water and steam contain water molecules, which means they are the same substance. However, the particles in steam are spaced farther apart compared to the closely packed molecules in liquid water, despite having the same temperature and therefore similar average kinetic energy.