which is the first step in the seafloor spreading process? a crack forms in oceanic crust. volcanoes erupt…

which is the first step in the seafloor spreading process? a crack forms in oceanic crust. volcanoes erupt under the ocean. molten rock rises up through the crust. dense plates are subducted under less dense plates.
Answer
Brief Explanations:
Seafloor spreading starts with a crack forming in the oceanic crust. This allows magma to rise. Eruptions and magma - rise occur after the crack forms. Subduction is part of plate - tectonics but not the first step of seafloor spreading.
Answer:
A. A crack forms in oceanic crust.