The correct answer to this question is D, crust. This outer layer is hard and made of igneous, metamorphic, and sedimentary rocks. The crust is 1% of the Earth's volume. There are two different types of crust. The first is the continental crust, which is thich and under the land.
The second is the oceanic crust, which is thinner and under the ocean. The crust is comprised of 46.6% oxygen, 27.7% silicon, 8.1% aluminum, 5% iron, and the other 12.6% is comprised of various other elements. The material of the crust is a family of sillicates, feldspars, quartz, and oxides.