Which of the following describes the build-up of land due to sediment deposition?

The correct answer is accretion, which refers specifically to the gradual accumulation of sediment or soil in an area, leading to an increase in land mass. This process typically occurs along riverbanks, deltas, and coastal regions where sediment carried by water settles and builds up over time. Accretion is a natural and often gradual phenomenon that contributes to the growth or expansion of land.

In contrast, erosion involves the removal and transportation of soil and rock from one location to another, which is the opposite of the build-up described in the question. Alluvium is the term used for the sediment that has been deposited by flowing water, but it doesn't indicate the process of land build-up itself. Reliction refers to the exposure of land previously covered by water as a result of a decrease in water levels, which also doesn't directly describe sediment deposition leading to land build-up. Accretion is the most accurate term to describe the process of land increasing due to sediment deposition.