Quote:
(A) sprang to life not in a flash of inspiration but evolved slowly
Hopefully, the “not… but” construction absolutely leaps off the page at you whenever you see it. It’s often treated as an idiom in GMAT test-prep books, but I think that’s a mistake: think of “not… but” phrases as strict demands for parallelism. Basically, the word “not” and the word “but” need to be followed by the same parts of speech (nouns, verbs, prepositions, modifiers, etc.) or else the sentence is wrong. (The same, of course, is true of “not only” and “but also”: whatever follows those two phrases need to be parallel to each other.)
And in this case, we have “not
in a flash of inspiration but
evolved slowly.” “Not” is followed by a prepositional phrase, and “but” is followed by a verb. That’s unambiguously wrong, so (A) is gone.
Quote:
(B) sprang to life not in a flash of inspiration but were slowly evolved
(B) has almost exactly the same error as (A): “not
in a flash of inspiration but
were slowly evolved.” “Not” is followed by a preposition, “but” is still followed by a verb. That’s still wrong. (B) is out.
Quote:
(C) did not spring to life in a flash of inspiration but evolved slowly
This one seems to work! “Did not
spring to life in a flash of inspiration but
evolved slowly…” Cool, the “not” and “but” are both followed by verbs, and they’re both in the past tense. That makes sense: they both happened in the past, and there’s no reason why those two actions should be in different tenses. We can keep (C).
Quote:
(D) did not spring to life in a flash of inspiration but had slowly evolved
Now we get into some subtle stuff about verb tense and meaning. (And we did a whole YouTube webinar on verb tense and meaning, so check this out if you’re interested:
https://www.youtube.com/watch?v=fxANHcxwbeM.) The past perfect tense (“had slowly evolved”) only makes sense if it describes an action that happened in the distant past, before some other “time marker” – usually a later action in simple past tense.
Superficially, we’re OK here: “had slowly evolved” is accompanied by the simple past action “did not spring to life.” But wait: the timeline is nonsense. This is literally saying that Edison’s inventions first “had evolved slowly” and THEN they “did not spring to life.” Huh? It makes much more sense to just use the simple past for both actions here.
So (D) can be eliminated.
Quote:
(E) did not spring to life in a flash of inspiration but they were slowly evolved
And now we’re back to a nice, straightforward parallelism error: “not” is followed by the verb “spring”, while the “but” is followed by “they were slowly evolved” – a clause that begins with a noun. Those things aren’t parallel, so (E) is gone, and (C) is our answer.