Final answer:
Adam is presenting the statistical aspect of argument by providing a specific percentage of cyberbullying victims who didn't know their tormentors.
Step-by-step explanation:
When Adam says, "Ybarra and colleagues discovered that 13 percent of cyberbullying victims did not know who was tormenting them," he is presenting the statistical aspect of argument. By providing a specific percentage, he is using data to support his claim. This statistic indicates that a significant portion of cyberbullying victims are unable to identify their tormentors.