Eating sharks will be of maximum risk.
Option D.
Step-by-step explanation:
Biomagnification is a phenomenon where a toxin which is present in the environment is taken by smaller organisms and the concentration of toxins increase in concentration in higher tropic levels.
Suppose a toxin is present in sea water. It's taken by the small algae along with water which isn't metabolized by the algae, but stored in their body. Now these algae are consumed by small phytoplankton which consume a lot of algae, and the toxin present in their body, which again gets stored due to no metabolism. This even increases into smaller fishes, larger fishes and then into shark which has the maximum toxin concentration. So consumption of sharks will be of maximum health risk.