Advice on which exam to take next??

I just took FAR and I'm waiting for the 1/13 score release. I'm waiting to go back to school to start studying for the next one but i'm undecided on which one to take next. I was thinking AUD because i just took a class this semester that helps with it, but then I was thinking maybe REG because I haven't taken a tax class in a whole year. Planning on taking ISC in April. HELP!