Word for "argument against my current position"?

Sorry about the badly phrased title. I’m not quite sure what I’m looking for, either.

My situation is that I’m writing a report arguing for the usage of A over B. I have listed many advantages of A, and disadvantages of B.

However, I also want to point out that B still has its own merits, and cases where it is better than A. Is there a word I can use to refer to the section that I argue in favor of B in?

The word would kind of mean arguing against my own current position, or arguing against oneself with intent of providing an alternate perspective.

Thanks!