The importance of seafloor spreading to the theory of plate tectonics is best described by:
Where new crust is created as plates move and pull apart.
Seafloor spreading explains how tectonic plates move away from each other at mid-ocean ridges, leading to the formation of new oceanic crust. This process is fundamental to the understanding of plate tectonics, as it provides evidence for the movement of plates and supports the idea of continental drift.