How should I start this letter?

I'm supposed to write a short-ish letter detailing "why I believe I'll be a successful student" to complete my readmission.

I know pretty much what I'm going to detail, but how the pineapple do I start that?
"I believe that I will..."
"During this past year that I have been out of school..."
"Dear College..."




Writing informal letters to professionals is slightly dumb. :(

The middle is a good start.

I'd probably go with the middle as well.

Middle one. Other two are too generic.

You should also consider writing the body of your letter first. Easier to facilitate and set the tone for the opening and conclusion imo.