Answer:
Option A : a bone or shell
Explanation:
The trace, preserved remains, and any other impression of organisms in the past is called fossils. The fossils are used for paleontology that is study of fossils which provides information regarding organism and their evolution.
A bone or shell can be preserved to study fossils and only imprints can be seen. As they are the hardest parts so can be preserved as they do not get decomposed easily but softer part do. So, an organism that died on land, an organ like an eye or lung, a complete large organism can be decomposed easily. Leaf imprints are used as fossils. Thus, correct option is a bone or shell.
