The general availability of high-quality electronic scanners and color printers for computers has made the counterfeiting of checks much easier. In order to deter such counterfeiting, several banks plan to issue to their corporate customers checks that contain dots too small to be accurately duplicated by any electronic scanner currently available; when such checks are scanned and printed, the dots seem to blend together in such a way that the word “VOID” appears on the check.
Conclusion - The new checks with smaller dots will be able to deter the counterfeiting of checks. (it is not a very short term plan)
What are we looking for - Something which is must for the conclusion to be true. Note - with the current tech. - printers and scanners if used to print new checks will print them with VOID. Passage doesn't talk about any technological advancements.
A questionable assumption of the plan is that
(A) in the territory served by the banks the proportion of counterfeit checks that are made using electronic scanners has remained approximately constant over the past few years
-- Irrelevant.
(B) most counterfeiters who use electronic scanners counterfeit checks only for relatively large amounts of money
-- Irrelevant
(C) the smallest dots on the proposed checks cannot be distinguished visually except under strong magnification
-- Irrelevant- Question is not - whether we can distinguish by looking or not.
(D) most corporations served by these banks will not have to pay more for the new checks than for traditional checks
-- Again , we are not concerned about corporations have to pay.
(E) the size of the smallest dots that generally available electronic scanners are able to reproduce accurately will not decrease significantly in the near future
-- Inline with our thinking. Must be true for the conclusion to be true. This is the correct answer.