Sorry, I made a mistake - glancing quickly I just assumed D and E had the same structure because they begin the same way. Only E uses a passive construction; D is active. But D has a few problems. When it says "the disease", that would normally refer back to the ailment mentioned earlier. This sentence makes perfect grammatical sense:
Author William Styron turned his despair into a harrowing yet illuminating account of the disease.
Here "the disease" refers back to "his despair", but that's not the intended meaning of the complete sentence - the disease in the sentence is 'depression'. So D starts having problems when it starts tacking things on at the end of the above, because it's not clear what the disease is supposed to be.
And when there is an obvious way to change an SC answer choice that would improve it dramatically, you're almost never looking at a correct answer. If you take the middle of answer D and change it so the sentence begins:
Author William Styron turned his despair into a harrowing yet illuminating account of depression, a disease from which he suffered
that immediately makes it a clearer sentence, which is a good reason to look for a different answer choice. The end of the sentence is also awkward, which is why I've left it out.