What happens when sedimentary rock becomes metamorphic rock?

A.
Sedimentary rock cools and solidifies to become metamorphic rock.

B.
Sedimentary rock weathers, erodes, compacts, and cements to become metamorphic rock.

C.
Sedimentary rock melts and crystallizes to become metamorphic rock.

D.
Sedimentary rock undergoes heat and pressure to form metamorphic rock.