I think that this is one rare occasion where 7sage doesn't do a great job of answering the question. #19 choice A isn't wrong because insular is incorrect (quite honestly it might be a better choice then misguided) however understanding the term "cosmopolitan" is the key. Insular and misguided are both not wrong, however admirable is also not wrong, but cosmopolitan is. I think this explanation needs to be changed.
Admin Note: https://classic.7sage.com/lsat_explanations/lsat-70-section-2-passage-3-passage/
https://classic.7sage.com/lsat_explanations/lsat-70-section-2-passage-3-questions/
For me taking the exam under time conditions is the most helpful tool to be prepared for the exam. So, it might be a lot, but I take a PT MWF, then blind review it and then Tue Thur drill anything I felt weak on the days before. I also struggle with RC as my logical games and LR range from 0-3 I have tended to emphasize RC a lot. Hope this bit of structure helps!