If if fossils of barnacles are found in a place then that place used to be covered by water in the past, then what fossils have to be found in a place to signify the place used to be covered by water?

Answer choices:
- bullfrogs
 - Sediment
 - Sea urchins
 - dinosaurs
 - barnacles
 - humans
 - patch reefs
 - natural gas

 

     barnacles     