Which marine ecosystem has the fewest available nutrients and the lowest productivity?
a) estuaries
b) open ocean
c) coral reefs
d) continental shelf

The correct answer is : Open Ocean

Since the open ocean is really far from the land soil, the water consist almost no nutrients . And since it's really far away from the coast, there's almost no productivity around here ( almost no human is brave enough to go to the open ocean)

Um can u take a picture of the work

The answer is c hope this