Question

how are metamorphic rocks formed?
sediments compacted together
heat & pressure
cooling magma
erosion

Explanation:

Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or other metamorphic rocks) are subjected to high heat and pressure. This process causes the minerals within the rocks to recrystallize and change their structure and composition. Sediments compacted together form sedimentary rocks. Cooling magma forms igneous rocks. Erosion is a process that breaks down rocks but does not form metamorphic rocks.

Answer:

Heat & pressure