What effect does a large catchment area of Himalayan rivers have on river flow?

Correct answer: It can add more water and tributary streams to the main river

Answer: B. A catchment, or drainage basin, is the area from which rainfall, snowmelt, and other surface water drain toward a river and its tributaries. A large Himalayan catchment can collect water from extensive mountain slopes, valleys, and adjoining plains. Many tributaries may join the main channel, increasing discharge, especially during snowmelt or heavy monsoon rain. B is correct because it describes the likely effect of a large basin: more collected water and tributary contributions. A is wrong because catchment size does not determine that a river must be inland or end without reaching the sea. C is wrong because a river’s source is in its headwaters, not the sea. D is wrong because Himalayan rivers commonly carry sediment produced by erosion; a large catchment does not make a river sediment-free. Memory cue: “larger basin, more collection points”; more tributaries usually mean greater flow, though flow varies with season.