I read a lot of discussion regarding the use of the Expletive “it” and questions regarding the nature of answer C.
In my opinion, if you break down the structure of B (the answer in which the OG states the usage of the Expletive “it” is correct) and the structure of C, it might seem a little more clear why the “it” in C should probably refer to a singular noun.
Concept: Generally, we can use a non referential (“expletive”) “it” to push back a ‘THAT’ Noun Clause functioning as a Subject. When we do so, the sentence construction becomes less awkward.
Ex: “It is now generally accepted that the GMAT is a difficult test.”
If we were to write the sentence using the ‘that’ clause in the Subject Slot, we would have:
“That the GMAT is a difficult test is now generally accepted.”
There are other cases that differ slightly from this exact construction, but this is the basic idea.
In B, we can correctly restructure the sentence, although it becomes awkward:
b. …. It may be that none is more concentrated (than) the wave.
inverted: … That none is more concentrated than the wave may be.
Hence, the use of the expletive “it” seems to make some sense (although the grammar may be questionable)
In C, the “that” appears to function more as a relative pronoun referring to and further describing “none”
If you notice in B, the indefinite pronoun “none” comes after the “that”. The structure makes clear that we have the non referential “it” pushing back a “that” noun clause.
However, in C we have
c. …. It is none that is more concentrated than the wave…
If we try to invert the sentence and make the “that” clause the subject, we end up with nonsense:
“That is more concentrated than the wave is none.”
The reason why this structure doesn’t appear to make any sense is because “that” no longer refers to its antecedent noun, “none”.
I believe the above is what might be going on with the usage of “it” in this question, but as many experts have pointed out, it is not wise to lose sleep over this grammatical construction (correct use of dummy “it”!! 😁 )
gtr022001
Of all the vast tides of migration that have swept through history,
maybe none is more concentrated as the wave that brought 12 million immigrants onto American shores in little more than three decades.
(A) maybe none is more concentrated as
(B) it may be that none is more concentrated as
(C) perhaps it is none that is more concentrated than
(D) maybe it is none that was more concentrated than
(E) perhaps none was more concentrated than
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