deep-sea currents earthquake formation spreading of the sea floor sedimentary rocks
I gave my students this multiple choice question: When scientists proposed the Theory of Continental Drift, there were many skeptics. Which discovery confirmed that the continents move on plates?

Only one answer is correct among these 4 choices:
- deep-sea currents
- earthquake formation
- spreading of the sea floor
- sedimentary rocks

Could you tell me which one is correct?

spreading of the sea floor