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. <em>Therefore we know this is not correct.</em>
Particles in liquid matter have more energy so they move around quite a lot, but not enough energy to bounce off one another. <em>Therefore we know this is not correct.</em>
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.<em>Therefore we know this is not correct.</em>
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).