What is the order of the rock cycle?

• A. Igneous rocks weather and erode to form sediments, which can form sedimentary rocks; sedimentary rocks can undergo metamorphism to form metamorphic rocks; metamorphic rocks can melt to form magma, restarting the cycle.
• B. Sedimentary rocks weather into igneous rocks directly.
• C. Metamorphic rocks form only from igneous rocks without melting.
• D. Igneous rocks weather into sediments only after melting.

Answer: (A)

The rock cycle is a continuous sequence of processes that transform rocks from one type to another through weathering, deposition, burial, lithification, metamorphism, melting, and solidification. The path described starts with igneous rocks breaking down by weathering and erosion into sediments. Those sediments are deposited and lithified to form sedimentary rocks. Under heat and pressure, sedimentary rocks (and other rock types) can be transformed into metamorphic rocks. If those rocks melt, they form magma, which can then cool and crystallize to become igneous rocks again, restarting the cycle. This sequence captures the major transitions and shows how the cycle is a loop rather than a one-way path.

Other options don’t reflect how the cycle works: weathering sedimentary rocks directly into igneous rocks skips the melting and crystallization step needed to form magma and then igneous rocks; metamorphic rocks can form from rocks other than igneous too, given heat and pressure, not only from igneous; and igneous rocks don’t require melting to be weathered into sediments—weathering acts on rocks at the surface regardless of their origin.