In a recent study of

Answer choices

1. A

   Weakens, if Anything13% picked this

   Any neurotransmitter that leaks from a damaged or oxygen-starved nerve cell will damage

   We didn't need to be convinced that glutamate will damage surrounding nerve cells (we had already been told that), so this is really only opening up the possibility of alternate causes, if there are other neurotransmitters that also could be the culprit in causing this brain damage.

   13%
2. B

   No Impact3% picked this

   Stroke patients exhibit a wide variety of abnormal chemical levels in

   A "wide variety of abnormal chemicals in their blood" is too unspecific to do anything. At worst, this is actually nudging in a weaken direction by suggesting that there might be other possible chemical levels that are off, and one of those might be causing the brain damage.

   3%
3. C

   No Impact31% picked this

   Glutamate is the only neurotransmitter that leaks from oxygen-starved or physically

   This is better than nothing, kind of, although we really don't care if other neurotransmitters leak. We'd only care if the other neurotransmitters were known to kill nerve cells (then they would be a potential alternate cause).

   31%
4. D

   Correct48% picked this

   Leakage from damaged or oxygen-starved nerve cells is the only possible source of glutamate

   Why this is right

   "the only" is a sufficient condition indicator (unlike "only / only if" which are both necessary indicators). Glutamate it leaked from damaged or in the blood ? oxygen-starved nerve cells We now know that the stroke patients in this study, the ones that had the highest levels of glutamate, definitely got that because glutamate leaked from damaged or oxygen-starved nerve cells. Wait, didn't we already know that? [Check the text] No, sneaky-sneaky. It was phrased as a conditional, with the if trigger hidden by putting it later in the sentence. If glutamate leaks, then the glutamate can kill nearby nerve cells. But in these stroke patients, did the glutamate leak? We were never told it did. Obviously, in order for the author's brain damage story to be correct, he's assuming that some glutamate leaked out of struggling nerve cells. This answer strengthens by establishing that assumption, as well as simultaneously ruling out all other possible explanations for having glutamate in the blood.

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

   48%
5. E

   Irrelevant / Weak5% picked this

   Nerve cells can suffer enough damage to leak glutamate without being

   Stuff as weakly worded as "some, can, may, sometimes" is almost always wrong on Strengthen, Weaken, Paradox. It's irrelevant to this argument whether the leaky cells are also killed. The author is only counting on glutamate killing surrounding cells.

   5%