Historian: In the Drindian Empire, censuses were conducted annually to determine the population of each village. Village census records for the last half of the 1600’s are remarkably complete. This very completeness makes one point stand out; in five different years, villages overwhelmingly reported significant population declines. Tellingly, each of those five years immediately followed an increase in a certain Drindian tax. This tax, which was assessed on villages, was computed by the central government using the annual census figures. Obviously, whenever the tax went up, villages had an especially powerful economic incentive to minimize the number of people they recorded; and concealing the size of a village’s population from government census takers would have been easy. Therefore, it is reasonable to think that the reported declines did not happen. In the historian’s argument, the two portions in boldface play which of the following roles?
A. The first supplies a context for the historian’s argument; the second acknowledges a consideration that has been used to argue against the position the historian seeks to establish.
B. The first presents evidence to support the position that the historian seeks to establish; the second acknowledges a consideration that has been used to argue against that position.
C. The first provides a context for certain evidence that supports the position that the historian seeks to establish; the second is that position.
D. The first is a position for which the historian argues; the second is an assumption that serves as the basis of that argument.
E. The first is an assumption that the historian explicitly makes in arguing for a certain position; the second acknowledges a consideration that calls that assumption into question.

Explanations please. I know the OA.

C it is..

Only war between C and E...

E isn't the case because assumptions are the phrases which ain't explicitly mentioned in the passage.. Moreover even if this is the assumption which is necessary to come to the conclusion, even then the second bold face is not ust a consideration.. It is the conclusion drawn by the author no matter how vague it may be...

see this period: Therefore, it is reasonable to think that the reported declines did not happen...it means that the census, actually, wasn't that complete. I believe E is the OA

yeah, I thought about that ..... but also C seems ambiguous....actually, we must say that if the census is complete, then the decline must be false and it is not a consequence of a wrong census..under this point of view OA seems C indeed...what do you think?

This one is actually pretty easy. Its just a long passage.
A: first part ok, no the second is his or her position.
B: second is not true.
C: first is a context. second is the position. OK
D: first is not a position.
E: first is not an assumption.