An estuary is
a. a freshwater biome
b. an area with a low concentration of minerals and nutrients
c. characterized by deep water
d. an ecotone
select the best answer from the choices provided

a. a freshwater biome

Explanation:

An estuary is a coastal water body of the Brackishwater body, with one or more rivers of the stream. Also is a transition zone between the marine and river environments. As an ecosystem Estuaries are under threat from the human activities of pollution and overfishing. Also threatened by coastal sediments and sewages., land runoff and industrial and agricultural such as plastics and heavy metals. Estuaries tend to be naturally eutrophic because land runoff discharges nutrients into the water body. An example of Chesapeake Bay once was full of oyster life that is now been wiped out due to pollution and overfishing. Hence, it proved that the sediments, nutrients, and algae can cause damages to these waters.