a footprint in a rock a seashell under water a leaf in a mudpuddle a bone on top of a sand pile
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Scientists study fossils to learn about extinct plants and animals. Which of these is the best example of a fossil?
Possibilities:
- a footprint in a rock
- a seashell under water
- a leaf in a mudpuddle
- a bone on top of a sand pile

a footprint in a rock