Which of these is most likely to help a teen have healthy online behavior?
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The correct answer would be B. Never posting anything you wouldn't say in person.
This would be healthy online teen behavior. Just because you are posting something online doesn't give anyone the right to say something to another person or voice an opinion that they wouldn't say in person. Too many people use the internet to hide behind and bully or troll other people and this is unhealthy disgusting behavior and only leads to upset.