Look at the diagram shown below. A diagram shows the rock cycle in Earth's crust. Magma can become igneous rock through cooling. Igneous rock can become magma by melting; metamorphic rock through heat and pressure, and sediments through weathering and erosion. Sediments can become sedimentary rock through compaction and cementation. Sedimentary rock can become metamorphic rock through heat and pressure, and sediments through weathering and erosion. Metamorphic rock can become magma by melting, and sediments through weathering and erosion. Which of these statements best summarizes the information provided by the diagram? (a) Metamorphic rocks change into magma in two steps. (b) Magma changes into sedimentary rocks in three steps. (c) Sedimentary rocks change into igneous rocks in two steps. (d) Igneous rocks change into sedimentary rocks in three steps.