C. Solid
The particles in a solid are held together by strong attractive forces so they can't move freely. However in gases and liquids the attractive force is weaker to they can move more easily.
I would say d
Hope that helps :)
Answer:
kinetic energy
Explanation:
When solids are heated the particles gain energy and start to vibrate faster and faster.
You could compare it to Washington D.C. It runs the cell as our capitol runs our government. It can be the "heart" of the cell. <span />