What natural phenomenon is primarily responsible for changing the earth's surface?

The correct answer identifies convection currents in the mantle as the primary natural phenomenon responsible for changing the Earth's surface. This is because these currents drive the movement of tectonic plates, which are sections of the Earth's crust. The movement of these plates can lead to various geological processes such as earthquakes, volcanic activity, and the formation of mountains and ocean basins.

In contrast, while wind erosion and water erosion do contribute to surface changes by weathering and transporting sediments, their impacts are secondary to the larger-scale movements caused by mantle convection. Solar radiation, while significant in influencing climate and weather patterns, does not directly alter the Earth's geological structure in the same way that tectonic processes do. Hence, the mantle's convection currents play a crucial role in the ongoing evolution of the Earth's surface over geological time.