Few politicians will support legislation that conflicts with their own self-interest. A case in point is August Frenson, who throughout his eight terms in office consistently opposed measures limiting the advantage incumbents enjoy over their challengers. Ttherefore, if such measures are to be enacted, they must result from direct popular vote rather than from legislative action. The case of August Frenson plays which one of the following roles in the argument? ['It demonstrates the extent to which incumbents have the advantage over challengers.', "It provides evidence, the falsity of which would guarantee the falsity of the author's conclusion.", 'It gives essential background information concerning a measure being advocated.', 'It is cited as an example illustrating the generalization that is invoked.']