The correct answer is option D. They recycle nutrients into the soil.
The wetlands are the water the land water bodies, which are supplied with the water seasonally or throughout the year. All the type of the wetlands can support growth of the life forms, which can be seasonal or annual. Some o the wetlands are polluted by human activities, but not all of them. Swamps are a type of wetlands.
All the wetlands are involved in the recycling of the nutrients back into the soil. A wetland system have a rich diversity of flora and fauna, which can help in filtration of various sediments from water, recycling or removing nutrients and pollutants. In the wetlands, the water also come from the runoffs, the inorganic substances present in the water can be filtered and added to the sediments.
