less dense than the mantle. made of a liquid material. made up of oxygen which is a light element. separated from the mantle by a layer of water.
I gave my students this multiple choice question: The continental crust floats on top of the mantle because the crust is

Only one answer is correct among these 4 choices:
- less dense than the mantle.
- made of a liquid material.
- made up of oxygen which is a light element.
- separated from the mantle by a layer of water.

Could you tell me which one is correct?

less dense than the mantle.