The correct answer is (b) Discharge and Sediment Load
The explanation is: As there is a risk of high floods in these rivers, the flood discharge and surface runoffs are unpredictable and this makes it tough to control them. Moreover, the sections which are required for the passing of these flood discharges are vastly out of proportion to the sections required for normal winter flows. So, therefore these variations in discharge and sediment load make the hydraulics of these rivers very complicated and cause them to meander.