The options for the question are:
a) Core
b) Mantle
c) Asthenosphere
d) Lithosphere
The correct answer is Lithosphere. Lithosphere is defined as hard outer part of the Earth that contains Crust and somewhat upper portion of the Mantle. The Earth's crust is made up Tectonic Plates which are in constant state of motion. So from the given options, Lithosphere is the correct answer.