The correct option is A 4
The relief features of Northern Plain are classified into 4 regions.These are Bhabar, Terai, bhangar and khadar.
Bhabar is a narrow belt comprising of pebble-studded rocks in the shape of porous beds.
Terai lies to the south of the bhabar belt. Streams and rivers re-emerge in terai.
Plain with older alluvium is called bhangar. It lies above the flood plains and consists of calcareous deposits (kankars).
Khadar are the young deposits of flood plains. These are very fertile and hence, good for cultivation.