The author argues in the original passage that scientists should have to disclose their conflicts of interest to let readers use this information in evaluating the scientists' scientific work.
Let's look at the answer choices to see where this use of the conflict of interests and open information is most clearly reflected.
(A) has nothing to do with disclosure - chuck it.
(B) also has nothing to do with disclosure - it's not the answer.
(C) is also not about disclosure - this is almost the opposite of what the author would want. He doesn't want to bar people from involvement but only that such insiders make their inside/conflicted position clear.
(D) is also not about disclosure, so it's out.
(E) looks a whole lot better - here again we see disclosure used as a way to allow conflicted parties to continue to participate in an activity, but still be open about their conflict giving other people the ability to evaluate how much they trust the conflicted parties' research/advice etc. Here's our answer.