Fact 1: Fossils are formed when layers of sediment cover the remains of organisms over time.

Fact 2: Sand and mud are examples of sediments.

Given the two facts above, answer the question "What covers remains to create fossils?" with the following options: 
- Sand and mud
 - Oxygen and water
 - Calcium carbonate
 - Volcanic ash
 - shells
 - some invertebrates
 - Water and oil
 - detritus


 

 Sand and mud        