Fossils are often hardened remains of organisms that once lived, such as a bone or tooth. Which characteristic of sedimentary rock makes it likely for fossils to be found in this type of rock?

A. An organism's remain become hardened when covered by melted rock.

B. Organisms are changed into rock by high temperature once they are no longer living.

C. The remains of organisms are buried under layers of sand, shells, and bits of rock.

D. The bones of an organism are pulled below Earth's surface during an earthquake.