What do scientists think the convection currents responsible for the movement of plates circulate through?

Question

Is it the lithosphere, inner core, rift valleys, asthenosphere/mantle?

I think its either the lithosphere or the asthenosphere/mantle but i can't figure it out..

Answer 1

According to the theory of plate tectonics, the convection currents exist in the magma in the asthenosphere. The currents are due to the unequal heating of the asthenosphere; the hotter, less dense magma rises, while the cooler, denser magma sinks.