Help me out~~~~~~

Here is the question,

When theories formerly considered to be ____ in their scientific objectivity are found instead to reflect a consistent observational and evaluative bias, then the presumed neutrality of science gives way to the recognition that categories of knowledge are human ____.
A. disinterested … constructions
B. callous … errors
C. verifiable … prejudices
D. convincing … imperatives
E. unassailable … fantasies

It's totally frustrating. I have no clue at all what the sentense is implying. :s:

Mine is the opinion of an ESL speaker but here's my guess:

I would prefer E: When theories formerly considered to be UNASSAILABLE in their scientific objectivity are found instead to reflect a consistent observational and evaluative bias, then the presumed neutrality of science gives way to the recognition that categories of knowledge are human FANTASIES.

The theories were believed to be objective and unassailable => then were found to be based on observations and evaluations that are NOT objective (are biased) => therefore one cannot rely on the neutrality of science, because bias means that categories of knowledge are subjective, i.e. the product of human fantasies.

I'd say C, because "prejudices" is to me the best antomym for "neutrality".

I'm afraid I paid more attention to the terms proposed than to the real meaning of the sentence.
In the first part, they use the word "neutrality", so I thought if the second part is in opposition with the first, then "prejudice" works fine as the contrary to "neutrality".