In butchery, the term "chine bone" refers to the backbone area of the rib section. Therefore, when butchers process a rack of ribs, they often start by removing the chine bone to separate the rib bones from the backbone.
Given that Chef A refers to cutting away the backbone, and Chef B indicates cutting away the chine bone (which is essentially the same thing), both descriptions are accurate in the context of removing the rib bones from the backbone.
Thus, the correct answer is:
D) Both chefs are correct.