Natural Science CLEP Prep 2025 – 400 Free Practice Questions to Pass the Exam

The other options, sedimentary, igneous, and metamorphic crusts, refer to the three types of rocks that make up the Earth's crust. While each of these types of crust may be present in various regions of the Earth's surface, they do not cover the majority of the surface itself. Continental crust, on the other hand, is the thicker and less dense layer of crust that covers most of the landmasses on Earth. This type of crust is composed mainly of granite and is less dense than oceanic crust, which is primarily composed of basalt. Therefore, continental crust is the correct answer as it covers most of the Earth's surface.