GMAT Sentence Correction (SC) | Re: Some scientists suggest the moon had been formed out of part

OE says that the use of which in A is wrong: the relative pronoun ???which??? must
refer to the immediately preceding noun, suggesting illogically in this case that ???the Earth??? was dislodged by a meteor.
I was under impression that the use of which is not so strict and that which can also refer to a group of words. Concretely, I thought that which could correctly refer to 'part of the Earth' in A and that A is wrong for other reasons.
Can which refer to part of the Earth in A?