pressure from a glacier heat from magma erosion from flowing water radiation from the Sun
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of these actions will change a sedimentary rock, such as limestone, into a metamorphic rock, such as marble?
Possibilities:
- pressure from a glacier
- heat from magma
- erosion from flowing water
- radiation from the Sun

heat from magma