The answer will be option #2: bullying that takes place using electronic technology
"Cyber" is a word that is associated with technology, and cyberbullying references to any type of bullying that is done through technology; specifically through the internet.
An example of cyberbullying would be posting mean comments on social media: it is a verbal attack at the victim through the internet; thus, it is cyberbullying.
Let me know if you need any clarifications, thanks!
~ Padoru