They both travel at the same speed. They are both waves. They are both electromagnetic. They both travel through a vacuum.
I gave my students this multiple choice question: How are light and sound similar?

Only one answer is correct among these 4 choices:
- They both travel at the same speed.
- They are both waves.
- They are both electromagnetic.
- They both travel through a vacuum.

Could you tell me which one is correct?

They are both waves.