Answer:
Crust is broken down
Step-by-step explanation:
In the formation os oceans, at first water fills the basins, in the second step segments of Earth's crust move and in the third step crust is broken down.
In the oceans when water fills the basin, it allows the Earth's crust to move which makes it folded or break apart. When the crust is broken down along with deep cracks, it is filled with water from streams and rainfall flowing in the ocean.
Hence, the correct option is "Crust is broken down".