You are presented with the quiz "Fan-shaped deposits of sediment form where?" 

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 "deltas are usually fan-shaped deposits of sediment that form where currents slow at a river's mouth". 

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


 

 mouth of rivers          