Limnetic, profundal, littoral, and benthic have what in common?

a. They refer to the upper-level zones found in salt- and freshwater ecosystems.

b. They are all zones found in freshwater systems.

c. They refer to the lower-level zones found in salt- and freshwater ecosystems.

d. They are all zones found in saltwater systems.
Please select the best answer from the choices provided

Α

B

C

D