Bunuel wrote:
Competition Mode Question
A history book written hundreds of years ago contains several inconsistencies. Some scholars argue that because the book contains inconsistencies, the author must have been getting information from more than one source.
The conclusion cited does not follow unless
(A) authors generally try to reconcile discrepancies between sources
(B) the inconsistencies would be apparent to the average reader of the history book at the present time
(C) the history book’s author used no source that contained inconsistencies repeated in the history book
(D) the author of the history book was aware of the kinds of inconsistencies that can arise when multiple sources are consulted
(E) the author of the history book was familiar with all of the available source material that was relevant to the history book
The question is "The conclusion cited does not follow UNLESS...." So this is a Disguised Assumption question. We have to find an answer choice that must be true so that the conclusion holds.
Interesting question. My take is as follows:
CONCLUSION: The author MUST have been getting information from MORE THAN ONE source
WHY?
BECAUSE his history book contains several inconsistencies.
(A), (B), and (D) are all irrelevant, and (E) somewhat STRENGTHENS the Conclusion but is not the Assumption. If we negate (E), it becomes: The author of the history book WAS NOT familiar with ALL of the available source material that was relevant to the history book. But the author MAY have been familiar with and getting information from MOST of the available source material. Negation of (E) does NOT break the Conclusion.
(C) is the required Assumption because if we negate (C), it becomes: The history book's author used SOME SOURCE that contained inconsistencies repeated in the history book. This breaks the conclusion that the author MUST have been getting information from MORE THAN ONE SOURCE. (C) excludes the possibility that the author used SOME SOURCE that contained inconsistencies ON ITS OWN, leaving the ONLY POSSIBILITY that the author got information from MULTIPLE SOURCES. (C) is correct.
I hope it helps you guys.