Particles in different states of matter move at different speeds, and act differently.
Particles in solid matter still vibrate, but they don't move because they have less energy. Therefore we know this is not correct.
Particles in liquid matter have more energy so they move around quite a lot, but not enough energy to bounce off one another. Therefore we know this is not correct.
Plasma is the state of matter with the most energy, so the particles move around a lot. But plasma is also made of ions and electrons, which both have electrical charges.Therefore we know this is not correct.
In gas form, particles have a lot of energy and they bounce around in their container, colliding off of each other.
Gas is correct, A).