Political commentator: Voters tend to elect the candidate whose visual image most evokes positive feelings. Thus, laws designed to increase the fairness of elections should not allow one candidate to buy significantly more media exposure than any rival candidates can afford. Which one of the following is an assumption on which the political commentator's argument depends? ['Elections are unfair only if at least one of the candidates has more resources than any rival candidate has.', "The tendency of a candidate's visual image to evoke positive feelings in voters at least sometimes increases as media exposure increases.", 'Candidates invariably buy as much media exposure as they can afford and campaign laws allow.', "People have positive feelings toward election candidates only when they find the candidates' visual images familiar."]