erosion from tidal action the deposition of sediment the flow of continental basalt movement from tectonic plates
I gave my students this multiple choice question: Scientists have measured the rate of growth of the Atlantic Ocean basin to be about 2 to 3 cm per year. This type of activity coincides with the formation of ridges on the ocean floor. What is the most likely cause of this activity?

Only one answer is correct among these 4 choices:
- erosion from tidal action
- the deposition of sediment
- the flow of continental basalt
- movement from tectonic plates

Could you tell me which one is correct?

movement from tectonic plates