by ManhattanPrepLSAT1 Wed May 29, 2013 11:21 pm
Hi charleneroche, good question.
This question takes a quite common form on the LSAT - particularly in Strengthen/Weaken questions. The argument provides some sort of observation (demand for books increased after the invention of the invention of the printing press) and the goes on to offer an explanation for why it happened (increase in the number of people who learned how to read).
The problem for an argument with this structure is that the provided explanation is only one of many possible explanations; maybe people suddenly had more expendable income, maybe there was increase of very high quality books that everyone wanted to read, or maybe as answer choice (C) points out the increase in books sold didn't come from an increase in readers, but from an increase in the number of books read by the same readers as before.
Incorrect Answers
(A) supports the argument's hypothesis that there was in increase in the number of people who could read (assuming that reading and writing are both aspects of the same phenomenon - literacy).
(B) is irrelevant, since this fails to indicate whether the people scribbling in the margins represented an increase in number of people who were actually reading those books.
(D) and (E) support the argument's hypothesis that there was increase in the number of people who could read.