GMAT Sentence Correction (SC) | Re: Rock samples taken from the remains of an asteroid about twice the siz

Rock samples taken from the remains of an asteroid about twice the size of the 6-mile-wide asteroid that eradicated the dinosaurshas been dated to be 3.47 billion years old and thus is evidence of the earliest known asteroid impact onEarth.

Plural Subject "Rock Samples" needs a plural verb "have" so option A and B are out

(A) has been dated to be 3.47 billion years old and thus is
Incorrect for the reason mentioned above
(B) has been dated at 3.47 billion years old and
...

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