Here is my take on it.
I will go with option E.
General availability of S and P made c'ing easier.
To deter such c'ing, bank made a plan : issue checks containing small dots that can not be accurately duplicated by S "currently available."
When new checks are scanned, VOID will appear.
Without looking at answer choices, "currently available" words pulled my attention about the scanners.
(A) OUT - Out of scope - It is bringing territory in to the picture.
(B) OUT - There is no reason to talk about large or small amounts of money.
(C) OUT - This is a good assumptions but the same meaning has already been conveyed in the passage. No need to re-iterate it again.
(D) OUT - This is a good one but it is not helping to connect the known facts that we already know.
(E) This is saying that Scanners that are available today (which can not accurately duplicate the small dots) WILL NOT DECREASE in the near future. So until then the solution provided (small dots - VOID) is good enough to deter counterfeiting of check frauds.
I could be wrong, please feel free to correct me if I am. Thanks.