It seems to me that this question is really testing knowledge of the parts of speech. If we look at the answer options, we see the following trend emerge:

A: stipulate --> looks like a verb to me.
B: scant --> this is an adjective.
C: laud --> verb.
D: sufficiency --> noun.
E: poverty --> noun.

We need a noun to complete this passage because it says she was buried in something. Since we're only given individual words, we can rule out something like a noun phrase.

We only have two options that fit the bill for being a noun and of those, one is obviously wrong -- "sufficiency". It says that Wilde, despite being the greatest, was buried basically with no indication of who she was and without any sort of recognition. I would say "poverty" -- implying something is lacking -- is a good fit here.

Hence, E.