4A and 4B Exams

Just wrote and passed my Part A exam through SAIT today, and was looking for some info on best course of action now. I have the textbooks for 4B, so I can enroll and start working on that part, but I've just read online that there are multiple ABSA exams for each, and was curious how this all worked or what the best course of action would be. Should I do the ABSA exam(s) for 4A now, then enroll in Part B? or should I do the course now and then the exams?

I had been under the impression there was only one class 4 exam after completion of the courses, so it was a bit of a surprise to learn that there are apparently multiple for A and B as far as I can tell?

Maybe someone can shed some light on the situation for me.