Geography · Geomorphology

Consider the following pairs with reference to types of rivers based on their relationship with geological structure and slope: I. Consequent rivers: Flow in conformity with the initial slope of the land surface II. Subsequent rivers: Develop along zones of structural weakness and often join the main stream at near right angles III. Obsequent rivers: Flow opposite to the direction of the original consequent drainage IV. Resequent rivers: Flow in the same general direction as the consequent streams but originate later How many of the pairs given above are correctly matched?