The correct answer is Option 4. Key Points Wetland is defined as areas of marshes, fen, peatland, or water whether natural or artificial, permanent or temporary with water. that is static or flowing, fresh, brackish, or salt including areas of marine water, the depth of which does not exceed six meters. These areas have the soil covered by water or are present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season. Wetlands, natural and manmade, freshwater or brackish, provide numerous ecological services. The wetlands essentially act as the ‘kidneys of the landscape’, filtering and capturing sediment, and helping settle it to the bed of the wetland and the plants use these nutrients to grow which supports the whole ecosystem. Hence Option 4 is correct. Importance of Wetlands: It helps to maintain sedimentation and balance of soil, helpful in water, carbon, and nutrient cycles. They filter, clean, and store water and thus act as kidneys for other ecosystems. It helps to regulate the amount of water as excess water from rainfall and floods gets absorbed and can be used in times of need. It is the source of livelihood through fishing and rice farming to travel, tourism, and water provision. Wetlands host a large variety of life, protect our coastlines, provide natural sponges against river flooding and store carbon dioxide to regulate climate change. They provide habitat for wildlife and migratory birds and help in the conservation of the environment. Counter Argument Wetlands are also known as the Kidneys of the landscape due to their natural ability to accommodate surface runoff and subsequently clean the water, protect against floods, and recharge the underground aquifers through percolation. Evaporation is also a process instigated by the formation of wetlands.