Question

along with subduction, what other process changes sedimentary rocks to metamorphic rocks?
gravity
oxygenation
weathering
temperature

Explanation:

Metamorphic rocks form when sedimentary (or igneous) rocks are subjected to high - temperature and high - pressure conditions. Subduction (where one tectonic plate moves under another) can create these conditions. Temperature is a key factor in the metamorphism process. Gravity alone doesn't transform sedimentary rocks to metamorphic rocks in the context of rock - type transformation. Oxygenation is more related to chemical reactions involving oxygen (e.g., rusting of iron) and not rock - type transformation. Weathering breaks down rocks (e.g., into smaller particles) rather than transforming them into a different type of rock (like metamorphic).

Answer:

temperature