What is the sediment brought by a river called?

Correct answer: Alluvium

The direct answer is B, alluvium. Alluvium is the loose material—such as sand, silt, clay, gravel and small rock particles—that a river carries and deposits. The river may erode material in one place, transport it in flowing water, and leave it behind when the current slows. These deposits can build floodplains, deltas and other fertile river landscapes. Option A, ice vapour, is not the geographical name for river-borne sediment; water vapour is a gas, while alluvium is solid deposited material. Option B is correct because it names the sediment brought and laid down by a river. Option C, lava, is molten rock released by a volcano, not soil and particles transported by ordinary river flow. Option D, ozone, is a form of oxygen in the atmosphere and has no connection with deposited river sediment. The fact chain is: weathering or erosion produces particles, the river transports them, and deposition leaves them as alluvium. Do not confuse alluvium with lava or atmospheric gases. Memory cue: alluvium means river-brought soil and sediment.