Getting Your Branch Choice

Hello, so I start ROTC this coming fall, and was wondering what candidates who get their first 1 or 2 choices for AD look like. I know a 300 PFT is a given, but what about other things? GPA? Extra Curriculars? If it helps, the branches I am looking at are 1. Infantry 2. Armor. 3. Intelligence, and maybe aviation.

Thanks.