A and d would be correct if it is multiple choice
Ok, that is not a question
Answer: (date)
Dear (name),
I just heard you are starting secondary school! I just wanted to let you know that there are going to be a couple issues. First, you might have trouble making friends, but dont worry, just be yourself! Second, Bullying, If you are getting bullied, tell a teacher or a trusted adult. Third, finding your classes, if you have trouble finding your classes, ask a teacher for directions!
Stay safe and have a good year!
With love,
(name)