Answer:
The answer is Temperature (Heat), Pressure and chemical activity of fluids.
Step-by-step explanation:
Metamorphic rocks result from the transformation of pre-existing rocks that have undergone structural and mineralogical changes under certain physical or chemical conditions such as temperature, pressure or chemical activity of the fluids. This type of modification is known as a process called metamorphism, in which igneous rocks or sedimentary rocks, when subjected to high temperatures, pressures or active fluids, cause changes in their composition, bringing new substances to them.