by ohthatpatrick Wed Jun 19, 2019 3:04 pm
My prephrase for function of this sentence was "it's the setup for the thesis of the whole passage".
That is actually how the Holy Pivot® usually works. RC passages begin with some background or some other people's points of view, and then you get the magical Pivot of
but ... yet ... however .... recently
which typically attunes us to what the author is REALLY writing this passage to talk about.
The only weird thing here is that this pivot doesn't come until the end of the 2nd paragraph (usually it would be at the end of the 1st or beginning of the 2nd).
The other broad RC pattern at play in this question is their formula for "purpose of a detail". If you search this forum for phrases like "primarily to / serves to / in order to", you'll see I've written this blurb about 200 times:
When they ask us about the function of a certain line, they are almost always giving us a correct answer that reinforces one of the bookend ideas: the bigger claim that comes either right before or right after the detail in question.
So (D) is extremely lovable, since the following sentence begins "We propose ....".
(B) would be incorrect because that sentence is NOT extending an explanation. It's doing the opposite. It's saying "the explanation works up until this point, but then you can't extend the explanation to work for later events as well."
I think you're liking it because we could touch-it up and have a workable answer:
(B) extend the scope of the author's inquiry beyond the initial causes of the Great Migration and into the causes of later events
As you said, the income gap was the initial cause of the Great Migration. The author explains the longer-than-expected momentum of the Great Migration differently: not based on income gap but based on "the cost of moving isn't so steep or intimidating now that my buddies are already there".
It would be imprecise to say that "the easier move" (the later event) is a cause of the Great Migration. First of all, it's not quite an event. It's just practical considerations that had changed. Secondly, it seems weird to say it "caused the Great Migration" when what the author is really arguing is "it sustained the Great Migration / it continued it longer than one would expect".
Hope this helps.