Adelta is formed by deposition of sediment at the mouth of a river by water fanning out, and after sediments are deposited, they are gradually buried by more sediments. Given these facts, what can lead to the gradual burial of more sediments among the following options:
- erosion
 - loose soil
 - an ocean
 - a wave
 - a delta
 - wind
 - a lake
 - flooding


 

     a delta    