geography Delta

What word goes with the definition
A triangle-shaped (deposit) landform at the mouth of a river as it empties into a body of water:

• weather
• delta
• landform

How is a delta formed ?

• streams slow down when they meet the ocean and deposit sediment. 
• a strong storm causes the sand to wash into the ocean.
•  landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water.

Matter that settles to the bottom of a river and deposited.

• levee
• erosion
• sediment
• barrier island