Fact 1: Adelta is formed by deposition of sediment at the mouth of a river by water fanning out.

Fact 2: Rivers provide a water supply.

Given the two facts above, answer the question "What is formed by deposition of sediment at the mouth of a water supply fanning out?" with the following options: 
- a hurricane
 - soils
 - a delta
 - an ocean
 - soft soil
 - an island
 - detritus
 - spring


 

   a delta      