Answer:
a. on flood plains soils tend to be nutrient-rich and fertile
Explanation:
A floodplain is an area of the land that is adjacent to the river or steam and that stretches the channels of the base to the enclosing valleys and the soi, usually, consist of clays and silt and sands and thus the meandering water erodes the downstream of the deposition of the silt behind the lands. It also represents the and by the fluvial terraces and in terms f the ecology they are diverse and most fertile lands ad thence the wetlands and the riparian zone are those of the soil as an intermediate supply of nutrient and thus are valuable for the agriculture.