The goblin fern, which requires

Answer choices

1. A

   Too Strong: wherever Reversed Logic5% picked this

   Wherever there is a thick layer of leaf litter in North American forests, goblin ferns

   By saying that "goblin fern requires thick leaf litter", we'd get this conditional: goblin fern present ? thick leaf litter This answer choice is just reversing that logic and saying, thick leaf litter ? goblin fern

   5%
2. B

   Too Strong: none Fake Opposite8% picked this

   None of the earthworms that are native to North America eat

   This is just taking a fact we were told a certain European earthworm eats leaf litter and then flipping both ideas oh, then non-European earthworms don't eat leaf litter? If we negated this answer, it might start to feel like an alternate explanation, "hey, author, some earthworms native to North America eat leaf litter!", but that's a very weak suggestion of an alternate cause. Are those earthworms also found in areas where goblin ferns have disappeared, but not in areas where goblin ferns still live? Until we know these other earthworms also have that relationship to goblin ferns, they're not going to be a very tempting alternative hypothesis.

   8%
3. C

   Too Specific: greater part5% picked this

   Dead leaves from goblin ferns make up the greater part of the layer of leaf litter on the forest floors where the

   Just because the goblin fern requires a thick layer of leaf litter doesn't imply that their dead leaves are the majority of the leaf litter in areas where they've vanished (or in areas where they presently live). Requiring thick leaf litter ? Being the primary contributor to leaf litter.

   5%
4. D

   Too Strong: no spots19% picked this

   There are no spots in the forests of North America where both goblin ferns and earthworms of the species

   The author said that there are no locations where goblin ferns are thriving that are also teeming with (full of) L. Rubellus. So, we'd never find both of them in great numbers in the same place, according to the author. But we still might find some numbers of each of them in the same place. We might say that there are no areas where live country music is thriving that are also teeming with fans of rap music. But there are still areas where both live country music and rap fans coexist.

   19%
5. E

   Correct62% picked this

   L. rubellus does not favor habitats where the leaf litter layer is considerably thinner than what is

   Why this is right

   This has the lovable "ruling-out" language we know is common to a lot of correct answers in Necessary Assumption: not "Not" answers are very easy to negate (just remove the "not"), and so we should test whether negating the answer creates an objection to the argument (if it does, then it's the correct answer). If we said to the author, "L. Rubellus favors habitats where the leaf litter is considerably thinner than what is required by goblin ferns", would that be an objection? Yes! That would pretty much ruin the plausibility of the author's hypothesis. She thought that goblin ferns were living in an area (thus, it had a thick layer of leaf litter), then L. Rubellus moved in, gobbled up leaf litter until it was unusually thin, and thus the goblin ferns were killed off. Negating this answer does serious harm to the plausibility of that story. L. Rubellus wouldn't be likely to move into an area where goblin ferns are, since the leaf litter would be considerably thicker than the habitats L. Rubellus favors. Given that we know L. Rubellus has moved into areas where goblin ferns used to live, this answer forces us to think that 1st - something thinned out the leaf litter (we still don't know what) 2nd - goblin ferns got killed off 3rd - L. Rubellus moved in, now that the leaf litter was to their liking

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

   62%