You are presented with the quiz "What is formed by deposition of sediment at the mouth of a water supply fanning out?" 

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 "rivers provide a water supply". 

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


 

   a delta        