They are all solids. They are all liquids. They are all minerals. They are all elements.
I gave my students this multiple choice question: What do ice, a rock, and a piece of aluminum have in common?

Only one answer is correct among these 4 choices:
- They are all solids.
- They are all liquids.
- They are all minerals.
- They are all elements.

Could you tell me which one is correct?

They are all solids.