What is the term used for a fertile region between two rivers?
A sandbar is an area of sand, gravel or fine sediment that sits above the water.
Alluvial fans are fan-shaped deposits of water-transported material (alluvium)
The word 'do' means two and 'ab' means water.
Doab means the riverine island where two rivers meet.
Doab term is used in India and Pakistan for the tongue lying between two converging rivers.
Oxbow lake, a small lake located in an abandoned meander loop of a river channel.
Above terms, explanation clears that option C is correct that is Doab is the term used for a fertile region between two rivers.