(C) inelegant and (F) efficacious are the credited responses.

Note that the new electronic databases are described as potentially insightful and powerful— the implication being that they are not living up to their potential. Thus, the word used in Blank (i) to describe hypotheses will reflect that shortcoming, in contrast with the inventive solutions achieved in the past, which should be described by a more positive term in Blank (ii). By process of elimination, we can rule out the two more positive choices for Blank (i) and the two negative, or lukewarm, choices for Blank (ii).

Blank (i)

(C) inelegant (in this context: unappealing and unnecessarily complicated) is consistent with the sense of unrealized potential set up at the beginning of the sentence.

(A) a creditable hypothesis is worthy of praise—and we’re looking for a more negative term here.

(B) a cogent hypothesis would be reasonable and convincing—no sense of unfulfilled potential here.

Blank (ii)

(F) efficacious (producing the desired result) gives us the positive spin we’re looking for on solutions achieved in the past.

(D) a solution that’s suspect would be questionable, and we’re looking for a more positive term here.

(E) adequate isn’t a negative term exactly (not like suspect, for instance), but it’s much weaker than efficacious. An adequate solution is just good enough, and wouldn’t qualify for the praise conveyed by inventive. (Would you want to be rated adequate at your next job performance review?)