Question

seafloor spreading is a process -
that occurs at ocean trenches in which oceanic crust is recycled.
that occurs at mid-ocean ridges in which oceanic crust is recycled.
that occurs at mid-ocean ridges in which oceanic crust is formed and gradually moves away from the ridge.
that occurs at ocean trenches in which oceanic crust is formed and gradually moves away from the ridge.

Explanation:

Define seafloor spreading

Seafloor spreading is a geologic process where tectonic plates split apart from each other, allowing magma to rise from the Earth's mantle and cool to form new oceanic crust.

Identify the location of crust formation

This creation of new oceanic crust occurs at divergent plate boundaries, specifically along mid-ocean ridges.

Identify the movement of the crust

As new crust is continuously formed at the ridge crest, the older crust is gradually pushed away from the ridge on both sides, leading to the expansion of the ocean basin.

Answer:

• that occurs at ocean trenches in which oceanic crust is recycled.
• that occurs at mid-ocean ridges in which oceanic crust is recycled.
• that occurs at mid-ocean ridges in which oceanic crust is formed and gradually moves away from the ridge. (Correct answer)
• that occurs at ocean trenches in which oceanic crust is formed and gradually moves away from the ridge.