A warning sign of a bully from the behaviors given above is A. losing friends suddenly.
What is a warning sign of a bully?
When kids get bullied in school, other kids will not want to associate with them so that they don't get bullied too.
This means that the kid will lose friends as soon as they start being bullied which might appear as sudden to an outside observer.
In conclusion, option A is correct.
Find out more on bullying at https://brainly.com/question/25667896.
