... the sort of justifications it does or does not get differ greatly.
In the above sentence, the verb 'differ' agrees with a plural. Is the subject 'sort' or 'justifications'sort or justifications? And, if 'sort' -sort, why is that not with an s.s?
Can anyone please explain this verb agreement? It sounds correct, but I seek an explanation of the subject, ideally providing grammatical terms.