Benthic organisms are those that dwell on the bottom of the sea or on the ocean floor. These include sponges, lobsters, crabs, clams, worms, etc. From the given choices, only the tuna will not qualify being benthic. Thus, the answer is letter D.
The answer is A. I hope this helps.
From an area of high concentration to an area of low concentration.
The two strands are antiparallel
