Sentence Correction

From Princeton Review practice test:

Believed to have originated from local hospitals, oceangoing garbage scows dump medical refuse that may provide an explanation for the existence of unacceptable levels of pollution at several local beaches.


A) Believed to have originated from local hospitals, oceangoing garbage scows dump medical refuse that

B) Oceangoing garbage scows dump medical refuse that is believed to have originated from local hospitals, and this

C) Oceangoing garbage scows dump medical refuse, believed to have originated from local hospitals, that

D) Originated, it is believed, from local hospitals, an oceangoing garbage scow dumps medical refuse and

E) Originating, it is believed, from local hospitals, oceangoing garbage scows dump medical refuse and

OA: B

I understand that it can't be "medical refuse" that "may provide an explanation," but I thought using "this" as a stand-alone pronoun was wrong?

tnkippen wrote: I understand that it can't be "medical refuse" that "may provide an explanation," but I thought using "this" as a stand-alone pronoun was wrong?

Option B is correct here.

Here "this" refers to "oceangoing garbage scows dump medical refuse".

What is the rule for using "this" as a pronoun? MGMAT seems to say to avoid it.

Anyone else?

I doubt that B would pass muster as a right answer on the actual GMAT. In B, the demonstrative pronoun this refers not to any acceptable antecedent but to the entire clause, oceangoing garbage scows dump medical refuse. That is, B means This fact may provide an explanation.

Though such usage is very common, it's wrong on the GMAT. The GMAT SC version of Standard Written English requires that this, like every pronoun, refer to some noun phrase, not to any clause. Informal English, certainly including spoken English, allows sentences like B, and so it probably sounds fine to most test-takers.

Most stand-alone uses of this and those in GMAT SC are wrong for precisely the reason B is wrong. That's why we at Manhattan GMAT say to avoid them. I don't have a list of all such wrong answers ready to hand, but I expect that all or almost all have other problems as well as the pronoun reference problem.

michaels, that is exactly what I was looking for (and suspected), especially since it was in the MGMAT SC book that I read to avoid this type of usage. Thank you!