Final answer:
The crust forms the thickest layer on the interior of the Earth.
Step-by-step explanation:
The correct answer is D) crust.
The crust is the outermost layer of the Earth and is relatively thin compared to the other layers. It is made up of solid rock and is divided into the continental crust and the oceanic crust.
The mantle is the layer beneath the crust and is much thicker. It is composed of hot, solid rock that flows very slowly over long periods of time.
Learn more about Earth Layers