Answer:
c)heat and pressure is the correct answer.
Explanation:
Rock change into a metamorphic rock by heat and pressure.
Metamorphic rocks are formed due to physical and chemical change by heat and pressure of existing rocks. The magma heat warms the enclosing rocks making them change.
The rocks buried underground in the Earth, when they are subjected to heat and pressure these rocks change into metamorphic rocks.The pressure crushes the rock to produce metamorphic rock.