http://classic.7sage.com/lsat_explanations/lsat-65-section-4-question-13/

I wanted to check my understanding on this question vis. all of yours. I got this question wrong, however, in my blind review, I noted a necessary assumption and wanted to see if it's actually necessary to the argument or if I'm fooling myself.

The n.assumption I identified was that the quality of the teachers are more important to the quality of the education than the size of the class. If this weren't true -- if something was more influential to the quality of the education than the quality of the teachers, e.g. class size -- then I don't see a way for the argument to possibly function, however, this isn't the answer. The answer states that there aren't any available qualified teachers. So I was wondering if the assumption I identified is truly required and just isn't one of the answer choices listed, or if I'm really deluded on this issue. Thanks!