Which abiotic factor is essential to all aquatic ecosystems excpet the ocean hydrothermal vents, and why?

a. phytoplankton, because it provides a source of food
b. salt, because it provides the necessary environment for organisms to move about
c. deep water, because it provides the necessary environment for organisms to move about
d. Sunlight, because it provides a source of energy***

4 answers

I commented on your other post, but I guess I'll move here. I think D is right.
it's b
What is it
WHAT ARE ALL THE ANSWERS :C