Black mage requirements?

So i'm trying to be smart and plan ahead and pre level up the secondary class I need, but all the sources seem divided as to what the second class is supposed to be, half say arcanist (which is what I started to level) and the other half says archer? can anyone confirm this one way or the other (someone who got the job maybe?)

thanks a ton guys!

You have to level archer to lvl 15 in order to become a black mage. I think the confusion stems from archers(ARC) and arcanists(ACN) similar acronyms.^^