Explanation

Creating a filter: once we get going with this prompt we see the word "unlike," so we know there's a comparison. That means that we want to confirm that the grammatical expression of comparison matches the intended meaning. It does not: stripping out the prepositional phrase starting with "of the non-academics," we see that "belief" is being compared with "peers." Since "belief" is the only of the two words in the underlined portion, that's the part that will have to change, so that we are comparing people with people. We go to the answer choices looking for this outcome.

Applying the filter: the other answer choices solve the comparison problem in (A), but they introduce other problems. In (B), "of the belief" and "proceedings being" are both questionable style. Choices (C) and (E) both have the same problem: "non-academics involved believing" is poor style -- we won't give the academics an -ing verb if we can give them a pure and simple verb. That's what (D) does. The correct answer is (D).