If you get only one bottle there are two bottles missing. All Kodak C-41 developers come in 3 bottles, part A, part B and part C. It is never just one bottle. It is never pre-mixed.
C-41B developer is what I use on my Jobo processor. I am not aware that Kodak offers C-41B developer other than in replenisher packages. They should be developer replenisher LORR. After mixing part A, B and C you will get Developer Replenisher LORR. You will have to add small amount of Developer Starter LORR to make it a true C-41B developer. Before adding starter LORR the replenisher has twice the potency as a developer replenisher. It needs only half of the quantity that a standard replenisher takes to replenish same number of rolls of ilm processed.
This makes me wonder if this means it also has twice the potency after adding starter to become developer. I have used it just as standard developer (I did add starter LORR). It produces absolutely excellent negatives. Does its capacity really doubles the standard developer? I don't know. Can any expert answer this question please?