Explanation

The opposite-direction trigger although and the clue tenuous display of solidarity indicate that the remainder of the sentence will explain that the solidarity is not heartfelt. Thus, the clue incensed requires that the blank mean something like anger. None of camaraderie, adulation, facetiousness, or hubris means anger, so eliminate choices (A), (C), (D), and (E). Rancor does mean anger, so select choice (B).

Hence option B is correct!