Which term is most suitable for a fertile tract between two rivers?

Correct answer: Doab

The direct answer is A, Doab. A doab is a fertile tract of land lying between two rivers. The word can be understood as “two waters”: “do” means two and “ab” means water. Rivers deposit fine alluvial soil on their floodplains, so land between rivers is often useful for farming. Step by step: identify the feature as land, notice that it lies between two rivers, and select the geographical term for that land unit, Doab. Option A is correct because it exactly describes this river-bounded tract. Option B, Pass, is a narrow route through mountains or hills, not land between rivers. Option C, Valley glacier, is a moving mass of ice flowing through a mountain valley, not a fertile plain. Option D, Ocean trench, is a very deep depression on the ocean floor, not a landform between rivers. Do not confuse a doab with a valley: a doab is defined by two rivers. Memory cue: “Do” plus “ab” means two waters.