You can assume that the shrimp boat with its floodlights on has anchored while it was still dark, so there is a good chance that its discarded bycatch has had a chance to attract kings. If the lit shrimp boat is no good, try the one getting all the attention, since fish have already been caught there. If your boat's freeboard is low enough, this is an excellent technique. The head-first thrust back overboard will force water through the fish's gills, giving it a quick oxygen fix. B. Not good.
Kings can bite or tear through a net, complicating a quick release.
Nets also remove protective slime. C. A fair tactic, provided you can do it without hitting the fish's gills. D. Good, provided you were unable to remove the hook without hurting the fish. Not an option. While a few fish may remain in deep water this late in the season, most will have moved inshore to feed on migrating bait schools.