What causes the seafloor to spread apart at mid-ocean ridges? Select one:

Waves in the ocean pull the plates away from each other.

Earth is growing in size, and the mid-ocean ridges are where the crust has cracked to allow Earth to get bigger.

Earth's magnetic field is so strong it pushes apart iron-filled rocks.

Hot magma rises through the boundary at mid-ocean ridges, creating new rock and pushing apart the plates.