Answer:
A trench would be formed, a ridge would develop, magma would be released and the crust would separate.
Explanation:
Look at the picture and try to identify the process. Once you have identified the process, think of the landforms formed and what processes are involved. The phrase "seafloor spreading" in the question tells us that this is an oceanic divergence process.
When two oceanic plates diverge (move apart), tensional forces are exerted. Fractures may occur (faulting) near the plate boundary. Magma rises at the zone of divergence (a large fracture between the two plates). It solidifies and builds up to form a mid-oceanic ridge, a central ridge dividing the ocean basin. The cooled magma forms a new sea floor between the diverging plates (sea floor spreading).
For your info, I only gave you the explanations for the options chosen and there are actually more landforms and processes that occur in oceanic divergence. If you want the full explanation of the entire process, let me know.
