Out of the listed functions of wetlands, the one that best reflects the analogy of "kidneys" is Aquatic plants absorb heavy metals and excess nutrients.

Here's why this function aligns with the kidney comparison Kidneys These vital organs in our body function as a filtering system, removing waste products and excess fluids from the blood. Wetlands With their dense vegetation and saturated soils, wetlands act as natural filters for water. Aquatic plants and microbes in wetlands play a crucial role in

• Phytoremediation Aquatic plants can absorb and accumulate heavy metals and other pollutants from water.
• Nutrient cycling Wetlands help regulate nutrient levels in water by absorbing excess nutrients like nitrogen and phosphorus. This prevents them from flowing into rivers, lakes, and oceans and causing harmful algal blooms.

By filtering pollutants and excess nutrients, wetlands help purify water and maintain healthy aquatic ecosystems. This aligns with the concept of kidneys filtering waste from our blood.