B、C选项为何不正确

问题如下：

Robin Herring, CFA, is a government bond research analyst at an independent credit rating agency. A competitor credit rating agency just downgraded the bonds of a government Herring follows. Herring notes that all of the information in the competitor's report was covered in his analysis published last week. In the past, Herring has been slow to downgrade bonds, so he starts to doubt his own analysis after seeing the competitor's report. Herring decides to reissue his credit rating of this government bond and match the competitor's downgrade. In his revised report, Herring states that new information has been made available to justify the downgrade. Herring posts the revision on the credit rating agency's website and provides it by e-mail to all clients who received the original. Herring's rating change least likely violated which of the following CFA Institute Code of Ethics and Standards of Professional Conduct?

选项：

A.Fair Dealing B.Communication with Clients C.Diligence and Reasonable Basis

解释：

A is correct because the analyst has dealt fairly with all clients by sending them an e-mail and posting his rating change on the credit rating agency's website when making material changes to his prior investment recommendation; therefore, he has not violated Standard l(B)-Fair Dealing. Clients should be treated fairly when material changes in a member's or candidate's prior investment recommendations are disseminated, which has been done.B is incorrect because the analyst has used the release of a competitor's report, contrary to his own previously published report, as a reason to revise his recommendation and has not used reasonable judgment in identifying which factors are important to his investment analyses, recommendations, or actions, as required by Standard V(B)-Communication with Clients and Prospective Clients.C is incorrect because the analyst does not have a reasonable or adequate basis for his downgrade, as required by Standard V(A)-Diligence and Reasonable Basis. The analyst has also violated Standard I(C)-Misrepresentation which prohibits making misrepresentations relating to investment analysis, recommendations, actions, or other professional activities.