Hine's emerald dragonflies are an

Answer choices

1. A

   Correct69% picked this

   Red devil crayfish dig chambers that remain filled with water even when the surrounding

   Why this is right

   This explains a way in which red devil crayfish can do something positive for the dragonfly population, and thus why dragonflies tend to remain healthier in habitats where red devil crayfish are present. If the red devil crayfish dig these special water caves, then the dragonfly larvae have an aquatic nursery to grow in, even when the surrounding wetlands dry up. LSAC went to the trouble of telling us (for no apparent reason at the time) that the dragonfly larvae "can survive only in the water". When we hear details like that, and they don't seem to have any initial important or relevance, the correct answer often has plans to use them in some way. My stupid nickname for this is "crumbs", like LSAC sprinkled little crumbs of details into the stimulus so that they would have a detail they could make use of in a correct answer. There's no real actionable takeaway from this -- it's more about test savvy and spidey-sense. If you feel like you're hearing an extraneous detail, you might just register the suspicion of, "That phrase seems unnecessary. I wonder if they're planning to use that somehow later."

   Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.

   69%
2. B

   No Impact19% picked this

   Red devil crayfish present no threat to adult Hine's

   This is neutral at best. But we need something that makes red devil crayfish (or the habitats where red devil crayfish are found) be a positive for the dragonflies. It needs to outweigh the negative fact that red devils are going to eat a bunch of dragonfly babies.

   19%
3. C

   No Impact6% picked this

   The varied diet of the red devil crayfish does not include any animal species that

   This rules out one of the potential correct answer ideas we considered. We were thinking, "Okay, okay, red devil crayfish do a bad thing for dragonflies -- they prey on dragonfly babies. But maybe they also do a good thing, like prey on species that would otherwise be preying on dragonflies." But this answer says, "Nope. They don't do this helpful thing for dragonflies."

   6%
4. D

   No Impact3% picked this

   Red devil crayfish are found in many more locations than Hine's

   It doesn't make a difference to us whether red devil crayfish are found in more habitats, whether dragonflies are, or whether they're found in a similar number of habitats. We need a reason why the red devil habitats are better for dragonflies than the habitats without red devils.

   3%
5. E

   No Impact4% picked this

   Populations of red devil crayfish in a wetland do not drop significantly if the local population of Hine's

   This answer is really saying nothing. It's saying "dragonflies do not have this effect on red devil crayfish populations". We're looking for an answer that says, "Red devil crayfish (or the habitats they're found in) do have this positive effect on dragonfly populations".

   4%