Answer:
The presence of high pressure and heat favors the formation of metamorphic rocks under the surface of earth.
Explanation:
Metamorphism process leads to the formation of metamorphic rocks. Metamorphic rocks are formed by the transitions of the existing earth's rock.
Metamorphic rocks are formed and remains stable under high temperature and pressure. These physical condition is available under the surface of the earth.
Hence, metamorphic rocks formed under the deep surface of earth.
