Final answer:
Rebecca's actions are best described as relational aggression, a form of indirect bullying that involves damaging someone's social relationships or status.
Step-by-step explanation:
The behaviors that Rebecca exhibits, which include spreading rumors about other students and isolating them from their peers, are best characterized as relational aggression. Relational aggression is a type of bullying that involves harm through the manipulation of relationships. It is often seen in the form of social exclusions, spreading rumors, and isolating individuals from social groups. This is different from physical aggression, which involves physically harming another person. Research finds gender differences in the types of bullying behaviors, where boys tend to engage in more direct, physical aggression, while girls tend to engage in indirect, relational forms of aggression.