What does the law of conservation of energy state?

a) energy can be created from nothing.
b) energy cannot be destroyed.
c) energy cannot change forms.
d) the total amount of energy in a system changes continuously.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.