#20 - In a recent study of stroke patients, those who

[Adam Tyson]

Exactly right, AM4747! The issue is not what the glutamate does, because that was given to us in the premises. Rather, it's where it came from. We found it in the blood, so it must have leaked from damaged nerve cells. What if instead it was ingested? Maybe it came from external contact? Maybe, as you said, it also is released by healthy nerve cells? The source of the glutamate, rather than the effect it has, is the issue here.

Well done!

[smtq123]

E is better at strengthening than D.
The argument doesn't associate Zero level of Glutamate with healthy nerve cells. In case of nerve damage, Glutamate has highest level. Like any item in blood test, we have normal levels of chemicals present, it is only when the values is outside the ranges then only it indicates some kind of abnormalities. So in the case of normal nerve cells (without any damage), it is very much possible to have lower levels of Glutamate in blood due to some natural reasons.
E strengthens as it rules out the possibility that nerve damage may prevent the release of Glutamate.
Looking for feedback on my analysis.
Thanks.

[Adam Tyson]

Sorry to break this to you, smtq123, but answer E has absolutely no impact on the argument. It doesn't matter at all whether the nerve cells from which the glutamate leaked were ultimately destroyed or not! So what if they were destroyed? They could still be the source of the leaked glutamate, or the source could still be something else!

As discussed earlier in this thread, the real issue in this argument is whether that glutamate we found in the blood could have gotten there some other way. We know it's there, and we know it can destroy surrounding nerve cells, and we know one possible source is leaking from damaged nerve cells, but what evidence is there that that MUST be the source? Answer D is the only one that helps to eliminate other possible sources, thereby strengthening the claim that it leaked from damaged nerve cells.