Critical Reasoning

In his new book on his complex scientific research, R frequently imputes bad faith to researchers disagreeing with him. A troubling aspect of R’s book is his stated conviction that other investigators’ funding sources often determine what “findings” those investigators report. Add to this that R has often shown himself to be arrogant, overly ambitious, and sometimes plain nasty, and it becomes clear that R’s book does not merit attention from serious professionals.
The author of the book review commits which one of the following reasoning errors?
(A) using an attack on the character of the writer of the book as evidence that this person is not competent on matters of scientific substance
(B) taking it for granted that an investigator is unlikely to report findings that are contrary to the interests of those funding the investigation
(C) dismissing a scientific theory by giving a biased account of it
(D) presenting as facts several assertions about the book under review that are based only on strong conviction and would be impossible for others to verify
(E) failing to distinguish between the criteria of being true and of being sufficiently interesting to merit attention

Oa is a.