The Correct Solution is Upper MantleThe asthenosphere is a part of the upper mantle just below the lithosphere.The asthenosphere lies below the lithosphere, between approximately 80 and 200 km below the surface, and extends as deep as 700 km.The upper part of the asthenosphere is the great rigid and brittle lithospheric plates of the Earth's crust move.Important PointsSIMA is found next to the SIAL Layer and it made up of Silica and MagnesiumThe lower mantle is the region inside the Earth that resides beneath the upper mantle.In this region, there is much greater pressure than in the upper mantleThe outer Core is the Third layer of the Earths surface and its mostly composed of liquid iron and nickel