If fossils of a water animal or plant are found in a place then that place used to be covered by water in the past, and most fossils are formed when sediment is deposited by wind or water. Given these facts, what type of material is a fossil formed among the following options:
- shells
 - coral reefs
 - In ice
 - On a leaf
 - unique
 - segmented
 - On grass
 - In sediment


 

        In sediment 