To answer this question, two key things need to be recognized. Firstly, the question is discussing the flood plain, hence one is looking at the mature to old stage of a river. Consequently, one wants to eliminate options that make reference to features associated with the young stage of a river. This means eliminating (D) with its reference to interfluves (i.e. the higher land between two valleys) and potholes. Secondly, one needs to recognize that landforms associated with gradational forces, other than rivers, are included. Therefore, (B) with its erratics (i.e. formed due to the action of glaciers) can be eliminated. With option (A) eskers are indeed formed by streams but within a glacier rather than on a river flood plain thus it is eliminated.

Consequently, only option (C) remains with its oxbow lakes (i.e. crescent- shaped lakes on a river flood plain formed when streams cut through the necks of meanders) and levees (i.e. banks of deposited alluvium on the sides of a river).