Why is C incorrect?

I am not an instructor, but I don't think answer choice C is addressing the passages main conclusion which is that there have been no audits completed. C is telling us that audits do not reveal significant violations....okay.....so why haven't they been published? For that reason answer choice is C seems slightly out of scope.

I am confused to why D is the answer.. Wouldn't in strengthen the argument??

Hey @etchun, @NaiemWoolfork, @DalilaPando, The best way to look at these is to start off with the error. What's wrong here? Well, this author seems to have a bit of tunnel vision. They see that no audits have been completed, and then jump to a conclusion that the tax agency somehow isn't following through on its plan? That would be like saying a mechanic isn't doing their job because they didn't change your oil. Just because it's a big part of the job, that hardly means they MUST do that every time to be considered working. D successfully weakens this argument, as it exposes exactly this fact - maybe they are still following through with the tax plan, but they just haven't completed any audits. It's like the mechanic - maybe they already checked the oil last time and don't need to this time. C, on the other hand, starts getting into the VALUE of audits, which was never discussed. Besides, even if the audits aren't all that effective...so what? That's like saying "there are more effective ways of changing the oil" to your mechanic. Ok...maybe there are, but they are still doing their job. Does this answer your questions?