The correct rationale for choice D being incorrect is its irrelevancy since physiological changes don't sway the argument.

In blind review, I interpreted the answer choice as relevant because if some of the fish didn't recover rapidly from physiological changes (aka. reproductive abnormalities - sentence 1), then even after the occasional mill shutdowns, though the hormone concentrations return, the physiological changes (aka. reproductive abnormalities) persist. So in essence, the recovery of hormones and dioxin decomposition don't matter at all since the physiological changes/abnormalities happen regardless once the fish contact the dioxin.

I think I'm jumping the gun with the physiological changes part because the crux of the argument is on the hormone concentrations, even if physiological changes happen after. I think I'm also assuming physiological changes equal reproductive abnormalities. Or even if physiological changes equal reproductive abnormalities, the recovery times don't matter. I'm probably not even addressing the premise the author gives and focusing on the context.

Admin Note: https://classic.7sage.com/lsat_explanations/lsat-45-section-1-question-12