Answer:
Date: July 2, 2021
Dear Teenager A,
I just want to let you know that it's not too late to say sorry to your parents. I advise you to stop breaking the school policies and flunking in classes. Also, please avoid drinking alcohol. You're too young to drink alcohol and it's not good for your health. Please apologize to your parents as soon as possible.
Your friend,
(your name)