Answer:
Apply high temperature and pressure to the rock
Explanation:
Igneous and sedimentary rocks can be turned into metamorphic rock when they are subjected to high pressure and temperatures. This naturally occurs when these rocks are overlaid by layers of other rocks/sediments and ‘crushed’ within the crust. This causes a realignment of the rock grains and also a change in their structure (recrystallization). An example is the metamorphosis of limestone sedimentary rock into marble.
