Passage Summary: Watanabe wants to kill trout to save salmon, but Lopez says the real problem is shrimp eating the baby salmon's food. Lopez thinks fixing the food problem is better than stopping the trout.

Conclusion: Lopez concludes that eradicating mysis shrimp is a better way to protect kokanee salmon than allowing trout fishing.

Reasoning: While trout eat adult salmon, the shrimp are causing the young salmon to starve by consuming their food supply (plankton).

Analysis: Lopez is shifting the focus from predation (trout eating adults) to survival of the young (shrimp causing starvation). To support Lopez, we need a principle that prioritizes addressing the root cause of a population's decline or protecting the most vulnerable stage of a life cycle. The argument assumes that stopping the starvation of the young is more effective or 'preferable' than stopping the eating of the adults. Look for an answer that establishes a rule favoring the elimination of the primary threat to a species' survival.