In the given picture the layer D depicts the crust. The earth crust can be define as the outermost solid hard part covering the geosphere. The earth's crust is hard outer part of earth. It is composed of rocks such as sedimentary, metamorphic, and igneous. The crust is of two types such as continental crust (it lies under the land) and the oceanic crust (it lies under the ocean). The continental crust is thick whereas the oceanic crust is thin.
