I'm not quite sure what is B and what is C. It is rather confusing during the construction. I believe that B (as an actual terminal check-in point) doesn't exist, but C check in and A check in (for int'l departures) end up in an airside-connected area which contains the decrepit A gates and the modern B gates (with no letter designation along with the gate #). The AR lounge (Skyteam, which would be used by DL) is further down the same pier (near approx. gate 16) as gate 9, so if you have access to one, you have access to the other.