GMAT Sentence Correction (SC) | Re: Test2-91. (29317-!-item-!-188;#058&004234) The

In Option B

, provided new insights into how comets.... is acting a modifier for the first part of the sentence.

However if we look closely than the first part below has no verb and hence a sentence fragment.
"The spectacular disintegrationof a comet last year in full view of ground- as well as space-based telescopes "
...

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