Why are liquids often dense?

I think it's B.

Because:

Increasing the temperature of water causes the molecules to spread farther apart. The farther apart the molecules are, the less dense the water is.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."