How do rivers help in agriculture?

Correct answer: By providing irrigation water and fertile soil

The direct answer is A, by providing irrigation water and fertile soil. Rivers are important to agriculture in two main ways. First, their water can be carried through canals, wells, pipelines or other irrigation systems to fields when rainfall is insufficient. Second, rivers deposit fine alluvial soil on floodplains and in deltas. This soil often contains useful mineral material and can support good crop growth when managed properly. Option B is impossible and harmful because rivers do not help farming by drying the sea. Option C concerns coral formations, not the normal agricultural role of rivers. Option D is unrelated: rivers do not help agriculture by lowering the Himalaya. Thus A gives both correct benefits—water and fertile alluvium. Floods can sometimes damage crops, so river benefits must be managed with embankments, planning and conservation, but the basic answer remains A. Memory cue: rivers bring water and alluvium; both support farming.