Sentence Correction (SC) | Re: After July, anyone disposing of or servicing refrigerators

"Those" is usually a pronoun on the GMAT (see the section on pronouns in ourTopic of the Week on "that" -- "those" is just a plural demonstrative pronoun), and in this case, it has no referent.

To be fair, I'm not 100% sure that you couldn't use "those" by itself on the GMAT, but I've never seen it used that way in an official question. And I don't think that this one is an official question,
...

---