Final answer:
The continental crust is thicker and less dense than the oceanic crust, which is made of mafic rocks like basalt and is younger due to continuous formation and recycling at plate boundaries.
Step-by-step explanation:
The relationship between continental and oceanic crust can be understood by comparing their composition, thickness, and age. The oceanic crust is mostly composed of mafic rock such as basalt and gabbro, which form from the cooling of mafic magma under the ocean. It typically lies submerged under the oceans, covering about 55% of the Earth's surface, and is approximately 6 kilometers thick. Conversely, the continental crust consists largely of igneous rocks like granite, and is significantly thicker, ranging from 20 to 70 kilometers. It covers 45% of the Earth's surface, some of which is also beneath the oceans. The continental crust is less dense and thicker than the oceanic crust, which is why it rises higher on the mantle, while the oceanic crust tends to sink, forming basins that become oceans when filled with water.
The correct answers to the question 'Which of the following correctly describe the relationship between continental and oceanic crust?' are that (c) Continental crust is thicker and (d) Oceanic crust is not primarily composed of granite; it is made up of basalt and gabbro. The oceanic crust is generally younger than the continental crust because it is constantly being produced at mid-ocean ridges and recycled into the mantle at subduction zones.