PT12.S1.Q24: Until recently it was thought that ink... "The hardest LR question ever"

atw_______

I was looking at the LR questions with the lowest correct answer rates and came across PT12 S1 Q24.

I picked A simply because the rest didn't make sense, but am confused why A is actually a flaw (as opposed to one that relies on the assumption that the Vinland Map wasn't also written by Gutenberg).

If the Vinland Map were also printed by Gutenberg, and we now know that Gutenberg was using this ink at the time, then it could be both likely that B-36 was printed by Gutenberg and that the Vinland Map is not a fake. None of that is inconsistent with the question stem.

So for A to be a flaw, we have to assume that the Vinland Map was not printed by Gutenberg. There is no evidence for that in the question stem. The only information we're given about the Vinland Map in the stem is that it was printed around the same time (the 15th century) as Gutenberg's works.

I get that it might be a reasonable assumption that the map wasn’t printed by Gutenberg, but feel like I’m missing something if a flaw can rely on an assumption that is not supported by the stem.

cjcjcjcj

Disregard everything that comes before the "since" phrase. The "since" phrase/aka the Sub C is the main part to look at.
First, the argument is stating two conclusions with only one evidence. One cannot conclude two things with only one evidence.

Plus, the two conclusions that the argument proposes contradict. Why? Because one thing cannot be said to be "unique" ("printed by Gutenberg") yet simultaneously be attributed as a practice of an entire century ("purportedly fifteenth-century").

Hope this helped.