The text does not provide any definitions, thus, options a. definition-example and cause-effect and c. comparison-contrast and definition-example can be out ruled...There are provided examples just not definitions. The text does show patterns of cause and effect--such can be shown with sentence (6) "Clearly the feeling of being anonymous causes people to engage in antisocial behavior." This sentence shows that the cause (anonymity) can lead to the effect (antisocial behavior). Hence, the correct option is b. cause-effect and comparison-contrast.
