Which logical fallacy is used in the text?
How could Vivian have anything insightful to say about foreign affairs? She grew up on a farm.

 - slippery slope fallacy: the false assumption that a small first step will lead to extreme consequences
 - ad hominem: an attack against the person making the argument, rather than the argument itself
 - bandwagon fallacy: the assumption that the popular choice is automatically correct
The text argues that Vivian cannot be insightful about foreign affairs because she grew up on a farm. This is a personal attack that isn't relevant to whether she knows about foreign affairs. This illustrates a type of logical fallacy known as ad hominem.