Where do subduction zones often occur?

a.
where a continental plate is being split into two parts

b.
where an oceanic plate is moving toward a continental plate

c.
where two oceanic plates are moving away from each other

d.
where two continental plates are colliding

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle