The correct answer is - B. Regulating the volume of cod fishing.
The cod was a fish that was very common on the menu in numerous countries. The big demand for it, led to an ever growing increase in the fishing of it. Because there were more and more cods fished, they were not able to sustain the pressure, did not had enough time to reproduce in order to maintain the numbers, so their numbers were going constantly down, to a point where it almost went extinct.
Realizing the danger, the governments implemented measures that were regulating the fishing of the cod, in order for the species to be able to recuperate and not go extinct. The strict measures were very effective, and the population of the cod started to recuperate, and be on a sustainable level.