What harassing behavior is portrayed by a person that obsessively follows their interest all the time?*1 pointBullyingExtortionStalkingWrestling

The behavior portrayed by a person that obsessively follows their interest all the time is best described as "Stalking."

Stalking involves an individual persistently following, observing, or contacting another person in a manner that would cause a reasonable person to feel fear. This behavior can manifest in various forms, including physical following, excessive communication, or other intrusive actions that disrupt the victim's life. In the context of an individual who excessively follows their interest, if that interest includes other people—such as obsessively tracking or frequently contacting someone without their consent—it can cross the line into stalking.

In contrast, bullying typically involves coercive behavior towards another person, extortion involves obtaining something through threats, and wrestling is a sport or form of physical contest and not related to obsessive or harassing behavior. Thus, stalking is the most appropriate term for such behavior.