Answer:
a. outer layer
Explanation:
lithosphere is right underneath the continental and ocean crust. it is approximately 100 km in deep and it is a brittle layer. It is broken into tectonic plates.
the inner core is located at the very center and its full of iron and nickel (so its not B)
on top of that is the outer core which is liquid (not D)
the middle portion of the mantle is the asthenosphere and mesosphere. they are right beneath the lithosphere. (not C)
so the best answer is A
