@yael, the issue with (B) is that the rest of the question is not making an argument about aesthetics but rather about the value of continuing to read and study Shakespeare's work. The original argument is that Shakespeare has always been appreciated by people of varied socio-economic standing, and the final couple of lines about the aesthetic aspects of the books is used counter the argument by claiming that only the rich could afford such books.
So the error in the argument is not that the author is using confusing a socio-economic argument with aesthetics but rather that the author is ignoring another possible explanation for the data. It's possibly that only rich people could afford the books of Shakespeare, but that doesn't mean that poorer people couldn't appreciate Shakespeare through live performance, etc.
