In general, is it safe to assume that when the conclusion in the stimulus has to do with something that someone "should" do, the right answer will also address that "should"?

For this question I didn't really look at C, D, or E because it didn't seem like they addressed the should claim so then I just looked at A and B because of the should piece, but I won't do that going forward if that's not a safe assumption.

In question 5, I'm confused why we should assume there is an "all" in front of spellcasters (making it group 1) instead of translating with "can't" and using group 4.