“Sentenza” was the cloze word here, I was a bit surprised by this one, I kept trying things along the lines of “frase”.
Unless this is a book describing a lot of judicial sentences passed, I do feel “sentenza” isn’t very appropriate here (e.g. none of the definitions I found on Treccani seem to correspond to the kind of “sentences” normally found in books or texts in general sentènza in Vocabolario - Treccani).
It appears that he might have been trying to be thorough in his coverage, although perhaps on this occasion it would have been better if he’d just left it at the straightforward interpretation.