Concluded that animals and, in fact, all living things are made of
cells.

4. Ancient sandstone beaches become buried deep beneath the Earth’s surface, where they are exposed to extreme heat and pressure.

Explanation:

Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found deep within the Earth or where tectonic plates meet.