B..
If he got three warnings, I believe he needed to be put in time out. She has other (I'm assuming paying) students to teach, as well. That was three times they were interrupted by your son. I don't think it's ridiculous, at all. Her actions sound very appropriate. Perhaps, the last teacher would let it slide. Your son likely acted the same way, but the teacher didn't do anything. I would prefer a teacher who did not allow my child to be disruptive. Would you allow your son to be disruptive in a school, or at home? Even after three warnings? If not, why allow it in public?