Option A is correct because sending an apology email saying 'I am sorry' is not an example of cyber bullying. According to the textbook context, cyber bullying is defined as 'any insulting, degrading or intimidating online behaviour like repeated posting of rumours, giving threats online, posting the victim's personal information, sexual harassment or comments aimed to publicly ridicule a victim.' It involves 'repeatedly targeting someone with intentions to hurt or embarrass.' An apology message does not insult, degrade, intimidate, threaten, or aim to hurt or embarrass the recipient. In contrast, Option B involves sending threatening messages, and Option C involves uploading embarrassing pictures to publicly ridicule someone - both of which clearly fall under cyber bullying as defined in the context.