The conclusion of the argument is: "treatment X should be preferred to treatment Y."
Why? Because studies have shown that treating certain illnesses with treatment X produces the same beneficial changes in patients' conditions as treating the same illnesses with treatment Y. And, treatment X is quicker and less expensive than treatment Y.
We are being asked to weaken the argument.
Answer choice (E) states "A third treatment, treatment Z, is even quicker and less expensive that treatment X."
Regardless of Z possibly being a better treatment, that has no effect on our argument that is trying to prove that X is better than Y. It is besides the point whether there are better treatments than X. We just want to know whether X is preferred to Y.
Hope that clears things up! Please let us know if you have any other questions.
Sallyanne-TejanMay 22, 2022
Would answer choice A not be out of scope considering they have both been equally as successful on patients?
Emil-KunkinMay 24, 2022
Hi Sallyanne,
While we are told that the two drugs had the same beneficial changes on (human) patients, we aren't actually told anything about the potential side effects. Perhaps they both cured some horrid disease, but one led to a painful rash. It wouldn't be inaccurate to say that both drugs had the same positive effect, although it would be incomplete.
It is also possible that the side effects had not shown up yet in human patients. Maybe the side effects only manifest after several years, and the animal tests were conducted before the human tests.
Finally, even if neither of these are true, (A) shows that one drug has the potential to have side effects. Even if they did not show up in human trials, this possibility should enough to prefer the other medicine, all else being equal.
