You are presented with the quiz "What can lead to the gradual burial of more sediments?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "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". 

So, what's the best answer to the question?


 

     a delta      