Even though she thought the informant was untrustworthy, the journalist promised not to reveal his identity so long as the information he provided did not tum out to be false. However, she will publicly reveal the informant' s identity if she is ordered to do so by a judge or her editor. After all, the information concerns safety violations at the power plant. Thus, the journalist will surely reveal the informant' s identity even if the information is accurate. The conclusion of the argument follows logically if which one of the following is assumed? ['The informant understood, at the time the journalist promised him confidentiality, that she would break this promise if ordered to do so by a judge.', "The journalist's editor will not order her to reveal the informant's identity unless the information is accurate and concerns public safety.", 'The information that the informant provided is known to be false.', "If the information concerns safety at the power plant, a judge will order the journalist to reveal her informant's identity."]