I don't THINK that was what LSAT had in mind to disqualify (A), but you're right that some students may have gotten confused thinking that we were HEARING Levi-Strauss's anthropological work, not arguing against it.
I'm pretty sure 'anthropology' means 'the study of cultures', so it seems to me like the discussion of the Hopi society and naming conventions definitely falls under the category of 'anthropological discussion'.
But there are still two problems with (A):
1. The passage does not present a 'study'. A passage presenting a study would have said something like, "However, in Katherine Morgan's recent work
Name Me a Rainbow, it is clear that Hopi names do much more than just refer to a noun", and then the passage would have elaborated on the facts contained in her study. This author just seems to be speaking from a place of knowledge about Hopi society and naming conventions. If I'm really knowledgeable about the career and songs of Nirvana and start talking about them for a couple paragraphs, that doesn't mean that I've presented a study.
2. The author's purpose was not as neutral as "presenting" / "describing" / "explaining". The author was definitely setting the stage by saying that he needs to "clarify a misconception".
(FYI, I'm also well-versed with Anthropologie ... 80% of the gifts I buy my wife have come from there)