Which phrase describes how metamorphic rocks form?

Metamorphic rocks are the rocks that arise from the conversion of existing rock types in a process called metamorphism, means changing of forms. Metamorphic rocks are formed from the other rocks that are changing because of heat or pressure applied. One of this example is the Earth movements that causing rocks to deeply bury or squeezed which will make the rocks heated and put under great pressure. They are not melting but the minerals they are containing are changed chemically that will form metamorphic rocks. Sometimes other rocks are formed when the others are close to some molten magma and getting heated.

If im wrong correct me

the answer is d.) potassium