A fossil is

• A. The remains of organisms trapped in dirt and chemicals, preserved and that show the history of evolution
• B. A living organism preserved in amber
• C. A DNA sequence used to date events
• D. A type of rock

Answer: (A)

What a fossil is: the preserved remains or traces of organisms that lived long ago. This fits best because fossils are physical evidence of past life, often formed when organisms are buried in sediment and minerals replace or encase their remains, or when traces like footprints or burrows are preserved. Fossils show the history of evolution by providing snapshots of organisms from different time periods, helping us see how species have changed over time. The other options miss this idea: a living organism preserved in amber would not be a fossil since it’s not a preserved remnant from the distant past; a DNA sequence used to date events is genetic data, not a fossil; and a type of rock is not a fossil itself, even though fossils can be found within rocks.