Explanation: This is an opening salutation of a formal business letter. Place a colon after the end of the salutation, not a semicolon. A comma is used only after an opening salutation in an e-mail.
A.
B. and C. both are missing commas in their sentences. A doesn't require a comma anywhere
Hi hun!
The answer to this question is going to be A.
-If you need me to explain more I gladly will just make a comment and I will let you know whatever you need!
-I hope this helps!!