Statistician: A financial magazine claimed that its survey of its subscribers showed that North Americans are more concerned about their personal finances than about politics. One question was: "Which do you think about more: politics or the joy of earning money? " This question is clearly biased. Also, the readers of the magazine are a self-selecting sample. Thus, there is reason to be skeptical about the conclusion drawn in the magazine' s survey. Each of the following, if true, would strengthen the statistician's argument EXCEPT: ['Other surveys suggest that North Americans are just as concerned about politics as they are about finances.', 'The conclusions drawn in most magazine surveys have eventually been disproved.', 'Other surveys suggest that North Americans are concerned not only with politics and finances, but also with social issues.', 'The credibility of the magazine has been called into question on a number of occasions.']