The wheel weighs less than the rod. The wheel weighs more than the rod. The wheel is made of the same substance as the rod. The wheel is made of a different substance than the rod.
I gave my students this multiple choice question: A blacksmith bends a metal rod into a round wheel. Which statement best describes the wheel?

Only one answer is correct among these 4 choices:
- The wheel weighs less than the rod.
- The wheel weighs more than the rod.
- The wheel is made of the same substance as the rod.
- The wheel is made of a different substance than the rod.

Could you tell me which one is correct?

The wheel is made of the same substance as the rod.