Complete Question Explanation
This Resolve the Paradox question involves a common scenario, the "surprisingly bad result". That is, we have something that is apparently very successful, like a great doctor or detective or some very stringent safety measures, coupled with an unexpectedly poor performance indicator, like the doctor having a high percentage of patients dying, the detective being unable to solve the majority of his cases, or a high degree of safety problems. Usually, the answer to these sorts of paradoxes is that things would be even worse if it were not for the great success of the first thing - if it weren't for that doctor's skill, even more patients would have died; if any other detective had been assigned those cases, even fewer would have been solved; if not for those stringent safety measures there would have been even more safety problems, etc.
Here we might expect something along those lines, something like "if not for the successful efforts of the government, counterfeiters would have found it to be even easier to pass their fakes off as real". However, in this case the "surprisingly bad result" answer isn't offered, and we need to try another tack.
The answer to almost every Resolve question is causal in nature. That is, we are looking for an answer that tells us what caused this perplexing state of affairs to arise in the first place. It may be that one of the two things somehow caused the other, as strange as that might seem, or it may be that some outside element, not mentioned in the stimulus, caused this paradox to occur. Look for an answer that goes beyond merely describing the paradox, or that tells us only how one side of the paradox came to pass, and which instead gives us a cause for the paradox. A good prephrase here might be "the success of the government program has caused all but the most skilled counterfeiters to give up this particular type of crime, so that only the most convincing counterfeits are now being passed to merchants and tellers."
Answer A: This answer helps explain one element of the successful government campaign against counterfeiting, but tells us nothing about why counterfeiters are having an easy time passing off fake bills. Since it fails to address both sides of the paradox it cannot resolve it for us. In fact, it makes the situation all the more hard to explain - why are counterfeiters having an easy time when these information campaigns have been so effective?
Answer B: Like answer A, this explains an element of the government's successful program, but tells us nothing about why the counterfeiters are having an easy time of it, and like A it deepens the mystery rather than resolving it.
Answer C: This answer is completely irrelevant - it doesn't address either the success of the government campaign or the ease counterfeiters are experiencing.
Answer D: This is the correct answer. Notice the causal language present. If it turns out that the success of the campaign has caused merchants and tellers to lower their guard, that would explain why counterfeiters are having an easy time passing off counterfeit money. The guardians have become lax due to a false sense of security and confidence. This answer provides a solid causal explanation that addresses both sides of the paradox.
Answer E: This appears to give no help to either side of the paradox, telling us nothing about the success of the program and nothing about the reported ease of passing off counterfeit money. Since it addresses neither side of the paradox and leaves us scratching our heads still wondering how the situation came to arise, it must be an incorrect answer.