One of the dangers of social media is that:

A. people can easily join an interest group.

B. you can find friends you have lost touch with.

C. job applications can be filled out online.

D. employers can use online activity against you.

The correct answer would be the fourth option D) because its true, posting stuff on social media can ruin your reputation in real life and make it harder for jobs to accept you since you are representing them, its not C) because that's a benefit, not B) because that's a benefit, not A) because that's not a danger so its D).