Existing rocks are buried and forced toward the mantie, increasing heat and pressure. this is the first step in the formation
of metamorphic rocks.
which best describes the next step in the formation of metamorphic rocks?
buried rocks melt deep within the mantle.
lava melts u rlying rocks, which crystallize into new minerals.
rocks that were buried are exposed at earth's surface, where they are weathered and eroded.
magma pockets rise, which increases heat, and minerals change due to temperature and pressure.

Option B, Lava melts u rlying rocks, which crystallize into new minerals.

Explanation:

Metamorphic rocks are the formed when the alternating heat and pressure are applied on an existing sedimentary or igneous rock. In the first step, a rock is forced down to reach the level of mantle where it experiences high temperature and pressure due to which it recrystallizes. Along with temperature and pressure, physical processes such as tectonic plate shifting and compression forces with in the rocks also compresses the rock into smaller volumes thereby making it more compact and dense. Therefore, all metamorphic rocks are denser than their original parent rock.  

Hence, the second step is option B

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".