Weegy: I am 100% sure its b. estuary,
These areas of transition between the land and the sea are driven by tides, like ... When fresh water meets salty seawater, both liquids combine turning into ... [ Estuaries can be called interior bays, lagoons, sounds or sloughs.
source:estuaries.noaa.gov/About/Default.aspx?ID=214? ] (More)