I felt dissatisfied with the answer choices for question 20. I easily eliminated A, D, and E as unsupported, but then struggled to choose between B and C.
(B) Wholly unregulated economies are probably the fastest in producing an equalization of social status.
(C) Expanded access to printed texts across a population has historically led to an increase in literacy in that population.
I did end up choosing C, because it felt like the smaller leap, (B is quite a big leap!) but both felt like leaps to me. I found the support for the inference in C in lines 18-22:
"Since printed materials have become widely available, however, people without special position or resources--and in numbers once thought impossible--can take literacy and the use of printed texts for granted."
What makes this an acceptable inference? That people can take literacy for granted once they have widely available printed materials? There seems to me to be a big gap here. (But maybe I'm really just attacking the passage's argument instead of interpreting it...)