Which logical fallacy is used in the text?
Jackson is not qualified to run the Environmental Club. Have you seen his sister's huge, horrifically inefficient car? The planet cries whenever she turns on the ignition.

 - slippery slope fallacy: the false assumption that a small first step will lead to extreme consequences
 - guilt by association: a negative association intended to discredit someone or something
 - straw man: a misrepresentation of an opponent's position that makes it easier to argue against
The text argues that Jackson isn't qualified to run the Environmental Club because his sister drives a fuel inefficient car. However, the behavior of Jackson's sister does not necessarily reflect Jackson's own behavior. This illustrates a type of logical fallacy known as guilt by association.