Explanation

Since Brookstone has lost several professional allies, and the blank describes something done against the university’s administration, a word that means something like attacks or opposition would make sense. Both approbations and commendations are nearly the opposite of what you’re looking for, so eliminate choices (A) and (E).

Neither precursors, which means predecessors, nor canons, which means accepted principles or rules, is supported by the sentence, so eliminate choices (D) and (F). Both tirades and diatribes mean angry speeches, so choices (B) and (C) give you appropriate, equivalent sentences.