Question

at the end of seafloor spreading, where does the molten rock solidify?
○ center of the ridge
○ on the edge of the ridge
○ under the new rock
○ between the old rock layers

Explanation:

Seafloor spreading occurs at mid-ocean ridges: molten rock rises at the ridge's center, then spreads outward and cools/solidifies as it moves away, forming new oceanic crust on the ridge's edges.

Answer:

on the edge of the ridge