GMAT Sentence Correction (SC) | Re: As a result of a supernova explosion, every human being on Earth was b

Option C: Notice the parallel structure X AND Y

X = neutrinos are harmless elementary particles produced in nuclear reactions (a complete clause)

Y = which interact very weakly with matter (a modifier)

Y should be a complete clause in order to make the sentence structurally complete. Hence C is wrong.

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Another way of looking at the parallel structure in C is :

X = produced
...

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