Sharon heard her favorite novelist speak out against a political candidate that Sharon has supported for years. As a result, Sharon' s estimation of the novelist declined but her estimation of the candidate did not change. The situation described above conforms most closely to which one of the following principles? ['Artists who speak out on political matters will have influence only among their most dedicated fans.', 'Someone who hears testimony that contradicts a long-standing opinion will generally entertain doubts about the source of the testimony rather than the correctness of the opinion.', 'Artists should limit their public political statements to issues that are somehow related to the arts.', 'A political statement from an artist should be considered only if the artist has established a reputation for being an honest and knowledgeable observer of politics.']