When you sign up for infantry they sign you up as 11X and tell they do a volunteer basis for 11C or 11B. It's bullshXX. They would never have any 11C that way. When you get to basic they will tell you what you are and there is nothing you can do to change it. If you reup you can switch, but you lose your bonus.Believe me I spent months upon months trying to switch to 11B. However your contract is not final until your final swear in before you leave. So if you need to change it do before your swear in and dont let them tell you no. Remember their job is to fufill the needs of the army not yours. Your just a another number to them. Also make sure you get a gaunteed duty station or you might get stuck in Ft Polk or Alaska