Grab your free copy of the June 2007 LSAT, turn to Section 2, #4, and cover up the answer choices. Now think of the dumbest person you know... try to picture their face. Got it? Okay. Now read the "Consumer" argument as if it was being made by your dumb guy or girl. Be critical as you read. The argument is dumb, right? Good. You've just done the single most important thing you can do on the LSAT.
If you ever find yourself nodding along with agreement as you read a Logical Reasoning question, then you're doing it wrong. Most of the arguments are terrible. Like this one. You'll be a better LSAT reader if you read critically. Don't take any shit!
Here, I can see two very commonly tested flaws. First, the dumb consumer has attacked the source of a study instead of addressing the actual merits of that study. Even though Danto Foods commissioned the study, and even if their PR department reviewed the study, that doesn't necessarily mean that the study is biased. (It's a hint, but it's certainly not proof.) This is a very commonly tested flaw.
The second flaw I can see is the flaw of concluding that, if the Danto study is flawed, then the opposite of the Danto study's conclusion must be true. This is like saying "you looked for life beyond Earth and didn't find it, therefore life beyond Earth conclusively doesn't exist." Well, no. If we haven't found it yet then we haven't proven it IS there, but it's also possible that we just haven't looked in the right places, or with the right tools. A failed attempt to prove something doesn't mean that the OPPOSITE has to be true.
Having armed myself with those two flaws, I can now look at the answer choices. This should be easy.
A) This answer actually encompasses both of my predicted flaws. It mentions the "apparent bias" issue, and mentions that such bias was used, inappropriately, as proof that whatever the study said must be false (rather than just unproven). This is a great answer. I'll read all five just to be sure, but this is pretty damn good.
B) We aren't told anything about the size or representativeness of the Ocksenfrey's sample. The argument would have to specifically give us this information in order for this to possibly be the answer.
C) What? I suppose the argument doesn't address this issue, but I don't think that's a flaw in the argument. Every argument, necessarily, "fails to take into account" almost everything... otherwise every argument would fill an entire library.
D) The nutrition value of Danto's foods isn't even in question here. The argument was solely about the Danto study, and whether or not it proves anything about Ocksenfrey.
E) I think the argument definitely does this, but I don't think it by itself is such a terrible flaw. In fact, it's probably fairly reasonable to assume that the PR department wouldn't be doing its job if it didn't try to censor a positive study about a competitor. I liked A, and I hated B-E. So our answer is A.