Laterite soil develops as a result of leaching. Leaching is the process by which minerals and nutrients are washed down through the soil by water. In areas with heavy rainfall, such as tropical regions, the water can easily wash away most of the soluble elements in the soil, leaving behind a soil that is rich in iron and aluminum oxides. This soil type is known as laterite soil.

Option 1, deposits of alluvial, is not correct because alluvial soil is formed by the deposition of sediment carried by rivers and streams, and it is different from laterite soil.

Option 2, deposits of loess, is not correct because loess is a type of wind-blown sediment that is rich in fine particles, such as silt, and it is not directly related to the formation of laterite soil.

Option 4, continued vegetation cover, is not correct because while vegetation can contribute to the weathering of rocks and the enrichment of soil, it is not the primary factor in the formation of laterite soil.