GMAT Sentence Correction (SC) | Sixty-five million years ago, according to some scientists,

Sixty-five million years ago, according to some scientists, an asteroid bigger than Mount Everest slammed into North America,which, causing plant and animal extinctions, marks the end of the geologic era known as the Cretaceous Period.

A. which, causing plant and animal extinctions, marks
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B.which caused the plant and animal extinctions marking

C.and causing plant and animal extinctions that mark

D. an event that caused plant and animal extinctions, andit marks
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