How are plateaus formed? When one tectonic plate subducts under another When the top of a mountain is broken off due to the force of gravity When magma under the earth's surface lifts up a large section of the crust When mining activities cause a mountain or hill to collapse

Plateaus are formed when magma under the earth's surface lifts up a large section of the crust. This process is known as volcanic activity. When magma rises from the earth's mantle, it can push up the overlying crust, forming a plateau. This can happen over millions of years as the magma continues to rise and solidify, adding layers to the plateau. Other options like tectonic plate subduction, gravity breaking off mountain top, and mining activities causing collapse are not the primary processes for plateau formation.