I think that the third paragraph provides fairly strong support for D, we are talking about a society where literacy was blossoming, but we have numerous examples of how many people would not have had access to written materials. Rather, they relied on oral testimony, speeches, and quotations of those written materials. That confirms D.
This is a must be true, it is asking what the passage said. Are there any answer choices that you think the passage supports? And how does it? Otherwise, it's really not possible to prove a negative, as what makes the wrong answers wrong is that the passage just didn't say that.
