Correct Answer: Estuary

Solution : The correct option isEstuary.

Because of the mixing of freshwater and saltwater, estuaries are the most productive ecosystems in the biosphere. An estuary is a partly contained body of water along the coast where freshwater from rivers and streams meets saltwater from the ocean. Estuaries are distinct and productive ecosystems that provide critical habitat for a variety of marine and terrestrial creatures. Their dynamic and changing circumstances are governed by tides, currents, and weather patterns.