The correct answer is C) At depths of about 50 to 200 hundred kilometers below the surface of the Earth.
To what depth below Earth's surface do you have to go before the pressure and temperature cause rocks to melt? At depths of about 50 to 200 hundred kilometers below the surface of the Earth.
The Asthenosphere is the layer of solid rock near its melting point. You can find magma at the Earth's core. Rocks melt into magma by three processes: Decompertion in the Mid-Ocean Ridge, the mountains chains under the water. Introducing volatile elements such as water or carbon dioxide. And Conductive heat.
The other options of the question were A) At depths of about 500 to 1000 hundred kilometers below the surface of the Earth, B) At the boundary of Earth's mantle and core, and D) At any point below Earth's crust.