Seafloor spreading occurs at divergent plate boundaries
Answer: Option B
Step-by-step explanation:
At divergent plate boundaries where the plates diverge from each other, sea floor spreading takes place. Sea floor spreading is the formation of a new oceanic crust.
The volcanic activity results in the formation of a new oceanic crust. Once the new oceanic crust is formed, it separates itself from the ridge and the plate boundary where it was formed. The formation of the new oceanic crust causes the tectonic plates to diverge more and more.