Students in a college ethics class were asked to judge whether two magazines had been morally delinquent in publishing a particular classified advertisement that was highly offensive in its demeaning portrayal of some people. They were told only that the first magazine had undertaken to screen all classified advertisements and reject for publication those it found offensive, whereas the second magazine' s policy was to publish any advertisement received from its subscribers. Most students judged the first magazine, but not the second, to have been morally delinquent in publishing the advertisement. Which one of the following principles, if established, provides the strongest justification for the judgment that the first magazine and not the second was morally delinquent? ['If two similar agents commit two similar actions, those agents should be held to the same standard of accountability.', 'Failure to uphold a moral standard is not necessarily a moral failing except for those who have specifically committed themselves to upholding that standard.', "A magazine should not be considered at fault for publishing a classified advertisement if that advertisement would not be offensive to any of the magazine's subscribers.", 'Anyone regularly transmitting messages to the public has a moral responsibility to monitor the content of those messages.']