Critical Reasoning

Joshua Smith's new novel was criticized by the book editor for The Daily Standard as implausible. That criticism, like so many other criticisms from the same source in the past, is completely unwarranted, as anyone who has actually read the novel would agree. Each one of the incidents in which Smith's hero gets involved is the kind of incident that could very well have happened to someone or other.
Which one of the following is the most serious error of reasoning in the argument?
(A) It relies on the assumption that a criticism can legitimately by dismissed as unwarranted if it is offended by someone who had previously displayed questionable judgment.
(B) It ignores the fact that people can agree about something even though what they agree about is not the case.
(C) It calls into question the intellectual integrity of the critic in order to avoid having to address the grounds on which the criticism is based.
(D) It takes for granted that a whole story will have a given characteristics if each of its parts has that characteristics.
(E) It attempts to justify its conclusion by citing reasons that most people would find plausible only if they were already convinced that the conclusion was true.