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This Q has been bugging me for a couple of days. Wouldn't the whole thing (including A as the best weakener) make way more sense if the argument said that the rate of extinction had been the same since 1970 -- and not just that the number of extinctions this year was equal to the number in 1970? Wasted a ton of time on this b/c it seemed like such a huge hole. I mean, what if the number of extinctions way outpaced the number of new species for every year 1971 to current year? (MLSAT forum touches on this but doesn't really answer it.)

I don't care so much about the question (got it right), but more about seeing if there's anything I can learn about my own blind spots. Am I missing something, or just over-reading the question (a tendency of mine)?