In recent years shrimp harvests by commercial fishermen in the South A

OFFICIAL EXPLANATION

If recreational fishermen were required to use large-mesh nets when fishing, fewer young shrimp would be trapped in those nets (making the reasonable assumptions, of course, that young, immature shrimp are smaller than mature shrimp and that by “large-mesh nets” is meant net with spaces big enough for young shrimp to pass through them). Thus, there is a strong likelihood that such a requirement would help increase commercial shrimp harvests. This makes C the best answer, and thus the correct answer.

A is incorrect. This requirement is most unlikely to bring relief; if anything, it will exacerbate the problem if commercial fishermen, too, start netting young shrimp. The second answer choice is also incorrect. This requirement would presumably make sense if the problem were caused by commercial fishermen catching too many mature shrimp. But the passage clearly indicates that the main problem is that too many young shrimp are netted before they reach maturity. D is not the correct answer choice. Since the problem lies mainly in the numbers of immature, and thus presumably small, shrimp that recreational fishermen catch, preventing those fishermen from catching large shrimp above a certain size is unlikely to provide an effective solution. The last answer choice is also incorrect. Nothing in the passage suggests that recreational fishermen are not already free to move into the open ocean if they own ocean-going craft. And if they are not already free to move into the open ocean, there is still nothing to suggest that they are interested in doing so in large enough numbers to relieve the over-fishing of young shrimp in estuaries.