What I did was I said the plates moved 3 centimeters per year and and times it by 100 million years and you get how far the plates have moved against each other. When they move that far against each other, the land would break and pile up to create mountains. Under the sea, the earth would collide and and create a chain of volcanoes. I got a 4/4 for this question, hope this helps you. Good luck!
