I would say the last one. The first two are dependent on the individual, and the school. The third is too general and difficult to find real statistics on. Honestly a better topic would be "Why" is cyber bullying the most popular method of bullying. You could do a whole section on comparing the amount of people who have experienced bullying in person vs. online. Another section on the different types of bullying used online, and many other ideas.
I feel as if this is more of an opinion. Although I would stick with the second option because it would have the most things to talk about and have the most evidence. Hope this helped!
