What factors led to the commercial extinction of northern cod?

Regulations safeguarding cod stocks did not evolve alongside the world's ability to harvest fish, and governments or international bodies sometimes assigned quotas based on economic factors rather than ecological ones. Although conservation became an increasing concern after the 1960s, officials consistently overestimated the size of cod stocks and, as a result, also overestimated the amount of cod fishers could harvest at sustainable levels.

the answer is c) an oak tree