Estuary is described as which of the following?

Estuary is described as which of the following?

• A. A deep ocean basin
• B. An area at a river mouth where freshwater and saltwater mix
• C. A coastal desert
• D. A mountain valley

Answer: (B)

An estuary is a coastal zone where a river meets the sea and freshwater mixes with saltwater. This mixing creates brackish conditions and a gradient of salinity influenced by tides, making these areas highly productive and rich in nutrients. That blend of river input and coastal influence is what defines an estuary. The other descriptions point to different environments—deep ocean basins are offshore, coastal deserts are arid land along the coast, and mountain valleys are inland landforms—so the description of an area at a river mouth where freshwater and saltwater mix is the best match.

An estuary is a coastal zone where a river meets the sea and freshwater mixes with saltwater. This mixing creates brackish conditions and a gradient of salinity influenced by tides, making these areas highly productive and rich in nutrients. That blend of river input and coastal influence is what defines an estuary. The other descriptions point to different environments—deep ocean basins are offshore, coastal deserts are arid land along the coast, and mountain valleys are inland landforms—so the description of an area at a river mouth where freshwater and saltwater mix is the best match.